Autosomal DNA Tests: Estimating Genetic Relationships and Discovering Relatives

In prior posts, I discussed the utility of Y-DNA tests as a possible avenue to gain insights and possible leads on identifying information about tracing the lineage associated with family surnames for the Griffis(ith)(es) family. [1] I have not discussed my experience of using autosomal DNA tests for genealogical and family research.

There are perhaps two unique things that atDNA tests can provide. They can:

  • identify unknown living relatives and their possible relationships; and
  • identify a possible relationship of a common ancestor that you share with a living relative.

My experience with atDNA tests have largely resulted in the initial discovery of many living third to fifth generational cousins. However, all of these distant cousins fail to document their respective lines of descent in various DNA company databases. The lack of this additional genealogical information makes it difficult to document where our common distant family connections are located.

A few of the genetic connections from the atDNA tests have provided documentation on common family connections. Based on their information, I have been able to identify a few distant connections. On two other occasions, I have discovered two half brothers.

This three part story focuses on the merits and limitations as well as my personal experience of using autosomal DNA (atDNA) tests for documenting genetic kinship ties in the Griffis family. This part provides general background to make sense of the DNA results. The second part of the story discusses my ongoing DNA discoveries from these tests. As such, the information can change in the future. The third part is devoted to my profound discovery of having two half siblings David and Greg.

General Comparison of DNA Tests

Depending on the DNA test, they tell you how much of their DNA you have inherited from unspecified ancestors on each side of your family or how far back you can trace genetic lineages through a maternal or paternal line. Genetic genealogy or results from DNA tests do not tell you where each member on your family tree lived or provide information on their specific family relationships.

DNA results can identify matches of living individuals and their possible shared kinship relationships. These estimates are based on the amount of shared DNA segments between the match and you. When it comes to identifying specific individuals and verifying kinship relationships, traditional genealogical research is typically required for interpretation of the results. [2]

There are basically three types of genetic tests used in genealogical research. Autosomal ancestry (atDNA), Y-DNA, and mitochondrial DNA (mtDNA) tests (see illustration one below). Autosomal tests can analyze a broader range of genetic family network ties than the Y-DNA or mtDNA tests. Y-DNA and mtDNA tests respectively trace the paternal and maternal sides of one’s genetic history. The atDNA tests are broader in their ability to trace genetic relatives on both sides of your family tree. However, their effectiveness of tracing ancestors is limited in terms of how many generations back they can effectively provide results. Another unique characteristic of the atDNA tests is matching living test takers through the amount of shared autosomal DNA.

Illustration One: Three Types of DNA Tests

Click for Larger View | Source: Modified version of an image found at Edward Sweeney, Types of DNA Test, MacDugall DNA Research Project, https://macdougalldna.org/types-of-dna-test-b/

As indicated in table one, while limited to the paternal line of descent, Y-DNA tests can effectively track male genetic descendants back around 300,000 years. Mitochondrial testing of the matrilineal line can also provide results that go back over 140 thousands of years. The popular atDNA ‘ethnicity’ tests can trace back through a limited number of generations. While women have two X chromosomes, DNA testing of the X-DNA is usually tested along with other chromosomes as part of an atDNA test. [3]

Table 1: Type of DNA Testing

CharacteristicAutosomal
DNA (atDNA)
Y – DNA (YDNA)Mitochondrial
DNA (mtDNA)
What does it test?All autosomal chromosomesY chromosomeMitochondria
Available toBoth males and
females
Only males can
take test
Both males and
females
How far back?5 – 9 generations~155,000 Years~200,000+ years
Source of TestingAutosomal
Chromosomes
Y ChromosomeX Chromosom
found in Mitochondria
What genealogical lines tested?All ancestry linesOnly Paternal (father’s
father’s father, etc)
Maternal (mother’s
mother’s mother, etc.)
Benefits – utilityFinding relatives within
a few generations, determining broader
ethnicity estimations,
identifying potential
matches across both sides
Tracing direct
paternal lines, surnames,
identifying specific
paternal lineages and haplogroups,
studying deep paternal ancestry
Tracing a direct
maternal line,
identifying maternal haplogroups,
analyzing ancient
ancestry patterns
Available from
the following
companies:
– ancestry.com
– Family Tree DNA
– 23andMe
– Myheritage
– Living DNA
– Family Tree DNA
– 23andME (high level)
– YSEQ
– Full Genome Corp
– Family Tree DNA
– 23andMe
– YSEQ
– Full Genome Corp

Autosomal DNA tests are useful for finding relatives, such as unknown relatives, clarifying uncertain family relationships and identifying distant relatives. Typically DNA companies identify matches up to six generations. The Y-DNA and mtDNA tests, while limited to only tracing paternal lines or maternal lines respectively, can trace genetic lineage back over 150,000 years.

Popularity of Autosomal DNA Tests

“For about a hundred dollars, it is now possible to spit into a tube, drop it in the mail, and within a couple of months gain access to a list of likely relatives. If you have any colonial American ancestors, the first thing you realize, taking a DNA test for genealogical purposes, is that potential sixth cousins are a whole lot easier to come by than you ever imagined. Even fifth cousins — people with whom you share a fourth great-grandparent — aren’t a particular scarcity.” [4]

These tests provide information about an individual’s ancestral roots, and they can help to connect people with their relatives, sometimes as distantly related as fourth or fifth cousins. Such information can be particularly useful when a person does not know their genealogical ancestry (eg. many adoptees and the descendants of forced migrants). [5]

The direct-to-consumer genetic testing market has shown significant growth in recent years, but there are indications of a recent slowdown in sales in 2023.

As many people purchased consumer DNA tests in 2018 as in all previous years combined. [6] Combined with prior years of personal consumer testing, more than 26 million consumers had added their DNA to ostensibly four leading commercial ancestry and health databases.

Chart One: atDNA Database Growth

Click for Larger View | Source: 23andMe Has More Than 10 Million Customers, April 8, 2019, The DNA Geek Blog, https://thednageek.com/23andme-has-more-than-10-million-customers/

In late 2019, there were signs of declining sales. Ancestry and 23andMe saw drops in direct website sales of 38% and 54% respectively compared to 2018. [7]

“Less than five years ago, consumer DNA tests were being hailed as the innovative technology of the future—but today, declining sales have forced several companies in the field to scale back their workforces and adjust their business strategies.” [8]

Market data from DNA companies suggest that the market continues to grow, albeit at a slower rate than the initial boom years. Projections include all type of DNA tests (e.g. genetic relatedness, ancestry, lifestyle wellness, reproductive health, personalized medicine, sports nutrition, reproductive health, diagnostics and others). Factors like market saturation among early adopters and privacy concerns may be contributing to the moderation in growth rates.

Despite the decade-long rise in sales, in 2020 there was a sudden decline in interest. Two of the leading companies, 23andMe and AncestryDNA, experienced declines in sales of DNA ancestry kits of 54 and 38 percent, respectively. The decline was attributed to market saturation, economic recession related to the COVID-19 pandemic, and privacy concerns. [9]

Since 2021, 23andMe, a prominent direct-to-consumer genetic testing company, has faced significant financial challenges that have raised concerns about its future and the security of customer data. The company’s financial situation has deteriorated rapidly. Its stock price has plummeted, losing over 97% of its value since going public in 2021. 23andMe is reportedly on the verge of bankruptcy and has never turned a profit.  In 2023, the company suffered a major data breach affecting nearly 7 million users. The company has had turnover of board members and internal dissension between board members and executive management. [10]

This situation surrounding 23andMe serves as a cautionary tale about the risks associated with entrusting sensitive genetic information to private companies and highlights the need for robust data protection measures in the rapidly evolving field of consumer genomics. It also underscores the need to have back up contingencies of one’s DNA data. [10a]

What do atDNA Tests Measure?

Autosomal DNA tests basically measure five things.

  1. Genetic Markers: atDNA tests look at hundreds of thousands of genetic markers in a DNA sample called single nucleotide polymorphisms (SNPs) across the 22 autosomal chromosome pairs. More on SNPs later in this story. These sampled SNPs represent DNA sequences that can be used to efficiently identify genetic differences and similarities between individuals.
  2. Inheritance Patterns: The tests examine the autosomal DNA inherited from both parents, which includes genetic contributions from all recent ancestors. This allows for connections to be made with relatives on all “recent” branches of a family tree, not just direct paternal or maternal lines in the past six or so generations.
  3. Genetic Relatives: The tests identify shared DNA segments between the test taker and other individuals in the DNA test company’s database, allowing for the discovery of genetic relatives that are living and linking each matched DNA tester to past generations.
  4. Ethnicity Estimates: By comparing an individual’s genetic markers to reference populations maintained by a DNA test company, autosomal DNA tests can provide estimates of a person’s ancestral origins and ethnic background.
  5. Health Traits: Many atDNA testing companies also include screening for certain inherited health conditions or physical traits that can play in one’s life to identify certain genetic code that could affect health.

The Genetic Influence of Autosomal DNA

An atDNA test is a measurement of sampled parts of your 22 autosomal chromosomes. Everyone (with rare exceptions) is born with a set of 23 pairs of chromosomes. The twenty-third chromosome is the sex chromosome. In most cases, we inherit an X chromosome from our mother and a Y or X chromossome from our father to determine our sex differentiation. (See illustration two).

Illustration Two: Karyotype of Human Chromosomes [11]

Click for Larger View | Source: Karyotype, National Genome Human Genome Research Institute, https://www.genome.gov/genetics-glossary/Karyotype

We inherit half of our chromosomes from our mother and the other half from our father. Two of those pairs are usually sex chromosomes (for most cases, XX in females and XY in males). The remaining 22 pairs of chromosomes are autosomal chromosomes or autosomes. For example, as illustrated below, chromosomes from the depicted mother are labeled in purple, and chromosomes from the depicted father are labeled in teal. (See illustration three).  [12]

Illustration Three: Inheritance of Parental Chromosomes

Click for Larger View| Source: Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

The genetic inheritance patterns associated with autosomal chromosomes become more complex and diluted over generations due to recombination and variable inheritance patterns. [13] Illustration four shows the average amount of atDNA inherited by all close relations up to the third cousin level. The illustration uses the maternal side as a an example. The percentages can be replicated for the paternal side. [14] As reflected in the chart, fifty percent of one’s atDNA is inherited from each parent and roughly equally portions from grandparents to about 3x great-grandparents. 

Illustration Four: Percent of Autosomal Genetic Inheritance from Descendants

Click for Larger View | Source: Dimario, A chart illustrating the different types of cousins, including genetic kinship marked within boxes in red which shows the actual genetic degree of relationship (gene share) with ‘self’ in percentage (%), 27 April 2010, Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Cousin_tree_(with_genetic_kinship).png

During meiosis [15], genetic recombination occurs, shuffling segments of DNA from each of the parents. This means that siblings may inherit different combinations of DNA segments from their parents; and with each generation, the specific segments inherited become more randomized. As a result, the amount of shared DNA between relatives decreases exponentially with each generation, making it more challenging to detect distant relationships through autosomal testing.

The random nature of genetic inheritance leads to variability in how much DNA is shared between relatives, especially for more distant relationships. This is known as variable expressivity. [16] For example, as indicated in table two, full siblings may share anywhere from about 35% to 65% of their DNA; and first cousins typically share around 12.5% of their DNA, but the actual range can vary significantly. This variability increases with more distant relationships, making it harder to precisely determine the degree of relatedness based solely on shared DNA percentages (see table two).  [17]

Table Two: Average Percent of Autosomal DNA Shared Between Selected Relatives

RelationshipAverage Percent
of DNA Shared
Range of DNA
Shared
Identical Twin100%N/A
Parent-Child50% (but 47.5% for father-son relationships)N/A
Full Sibiling50%38% – 61%
Half Sibling
Grandparent / Grandchild
Aunt / Uncle
Niece / Nephew
25%17% – 34%
1st Cousin
Great-grandparent
Great-grandchild
Great-Uncle / Aunt
Great Nephew / Niece
12.5%4% – 23%
1st Cousin once removed
Half first cousin
6.25%2% – 11.5%
2nd Cousin3.13%2% – 6%
2nd Cousin once removed
Half second cousin
1.5%0.6% – 2.5%
3rd Cousin0.78%0% – 2.2%
4th Cousin0.20%0% – 0.8%
5th Cousin
to Distant Cousin
0.05%
Source: Average Percent DNA Shared Between Relatives, 23andMe Customer Care, Tools, 23andMe, https://customercare.23andme.com/hc/en-us/articles/212170668-Average-Percent-DNA-Shared-Between-Relatives

While autosomal DNA testing has become increasingly accurate, there are still limitations in the context of estimating genetic relations and finding relatives. Current testing methods typically analyze only a subset of genetic markers. In addition, the interpretation of results relies on comparison to reference populations, which may not fully represent all ancestral groups. In the end, as previously stated, traditional genealogical research brings atDNA results into focus.

Genetic Variants: The Genetic Basis of atDNA Testing

genome is the complete set of DNA instructions found in every cell. [18] As discussed in a prior story, the human cell is a masterpiece of data compression. [19] Its nucleus, just a few microns wide, contains (if you ‘spell’ it out) six feet of genetic code comprised in a double helix called the DNA: deoxyribonucleic acid (see illustration five).

Illustration Five: Structure of Deoxyribonucleaic Acid (DNA)

Source: Modified image of DNA as found in Ruairo J Mackenie, DNA vs. RNA – 5 Key Differences and Comparison, 18 Dec 2020, updated 24 Jan 2024, Technology Networks, Genomics Research, https://www.technologynetworks.com/genomics/lists/what-are-the-key-differences-between-dna-and-rna-296719

The DNA helical molecules string together some three billion pairs of nucleotides that are comprised of proteins, sugar (deoxyribose), a phosphate and four types of nitrogenous bases which are represented by an initial: A (adenine), C (cytosine), G (guanine), and T (thymine). Nucleotides are the fundamental building blocks that make up the DNA strands. The sequence of nucleotides along the DNA strand encodes genetic information and regulates when codes are activated. [20]

The nucleotides form base pairs and are the cornerstone of genetic testing. (See illustration six.) They are the foundation of the programming language of our genetic code. Whenever a particular base is present on one side of a strand of the DNA, its complementary base is found on the other side. Guanine always pairs with cytosine. Thymine always pairs with adenine. So one can write the DNA sequence by listing the bases along either one of the two sides or strands. When DNA companies perform their tests, they essentially separate the two stands of the helix and use one side of the helix as the template or coding strand when they map out an individual’s DNA results.

Illustration Six: Relationship between Nucleotides, Base Pairs, Chromosomes, Genes, and DNA

Approximately 2% of our genome encodes proteins – this is where gene strands are located (illustration seven).  Coding “gene” DNA makes up only about one to three percent of the human genome, while noncoding DNA comprises approximately 97-99% of our total genetic material. This distribution shows that the vast majority of our genome consists of noncoding sequences. [21]

Genes are the basic unit of inherited DNA and carry information for making proteins, which perform important functions in your body. The coded regions of the genome produce proteins with structural, functional, and regulatory roles in cells and to a larger extent the human body. The remainder of our genome is made of noncoding DNA, sometimes called “junk DNA”, which is a misnomer. It is estimated that between 25% and 80% of non-coding DNA regulates gene expression (e.g. when, where, and for how long a gene is turned on to make a protein). [22] The non-coding DNA that does not regulate gene activity is composed either of deactivated genes that were once useful for our non-human ancestors (like a tail) or parasitic DNA from virus that have entered our genome and replicated themselves hundreds or thousands of times over the generations, or generally serve no purpose in the host organism.

Illustration Seven: Coding and Non-Coding Regions of the Genome

Clck for Larger View | Source: Modified version of graphic found at – Non-Coding DNA, AncestryDNA Learning Hub, https://www.ancestry.com/c/dna-learning-hub/junk-dna

Out of 3.2 billion DNA letters or nucleotides, there are only a ‘handful of places’ on the DNA ribbon that might be different between individuals. Humans share a very high percentage of their DNA. The exact figure is subject to some debate and depends on how it is measured. The commonly cited figure is that humans are 99.9% genetically identical. More recent research suggests a slightly lower, but still very high, level of similarity. Humans share a very high percentage of their DNA – roughly 99.4% to 99.9%. The small differences of 0.1 and 0.6 between individuals are crucial for understanding human diversity and health. [23]

As indicated in illustration eight, there are multiple types of genomic variants that comprise 0.4 percent of the genome.. The smallest genomic variants are known as single-nucleotide variants (SNVs). Each SNV reflects a difference in a single nucleotide (or letter) in the DNA chain. For a given SNV, the DNA letter at that genomic position might be a C in one person but a T in another person as reflected in illustration nine. [24]

Illustration Eight: Potential Sources of Genetic Variants for atDNA Testing

Click for Larger View | Source: Modification of a chart found at – Chart Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

Single-nucleotide variants (SNVs) are differences of one nucleotide at a specific location in the genome. An individual may have different nucleotides at a specific location on each chromosome (getting a different one from each parent), such as with Person 1 in illustration nine. An individual may also have the same nucleotide at such a location on both chromosomes, such as with Person 2 and Person 3 in the illustration.

Illustration Nine: An Example of a single-nucleotide variant (SNV)

Click for Larger View | Source: Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

As reflected in illustration ten below, there are also a small group of genetic variants that are called insertions and deletions of nucleotides.

“Insertion/deletion variants reflect extra or missing DNA nucleotides in the genome, respectively, and typically involve fewer than 50 nucleotides. Insertion/deletion variants are less frequent than SNVs but can sometimes have a larger impact on health and disease (e.g., by disrupting the function of a gene that encodes an important protein).” [25]

One of the most common types of insertion/deletion variants are tandem repeats. [26] Tandem Repeats are short stretches of nucleotides that are repeated multiple times and are highly variable among people. Different chromosomes can vary in the number of times such short nucleotide stretches are repeated, ranging from a few times to hundreds of times.

Each person has a collection of different genomic variants. For example, in illustration ten below, Person 1 has an insertion variant; Person 2 has a SNV and deletion variant; and Person 3 has an insertion, SNV, and deletion variant. All three people have different tandem repeats. Different variants can be inherited from different parents as reflected in the illustration.

Illustration Ten: Examples of Other Types of Genetic Variants

Click for Larger View | Source: Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

As indicated in illustration seven above, the third general type of genomic variations are structural variants (SVs). Structural variants extend beyond small stretches of nucleotides to larger chromosomal regions. These large-scale genomic differences involve at least 50 nucleotides and as many as thousands of nucleotides that have been inserted, deleted, inverted or moved from one part of the genome to another. [27]

Tandem repeats that contain more than 50 nucleotides are considered structural variants. In fact, such large tandem repeats account for nearly half of the structural variants present in human genomes. When a structural variant reflects differences in the total number of nucleotides involved, it is called a copy number variant (CNV). CNVs are distinguished from other structural variants, such as inversions and translocations, because the latter types often do not involve a difference in the total number of nucleotides. [28]

Cornerstone of atDNA Testing: Single Nucleotide Polymorphisms (SNPs)

A subtype of SNVs is the single-nucleotide polymorphism (SNP), pronounced as “snip” for short. To be considered a SNP, a SNV must be present in at least 1% of the human population. As such, a SNP is more common than the rare single-nucleotide differences.  [29]

Among the genetic variants, SNPs are relatively common, occurring approximately once every 500-1000 base pairs in the human genome. This translates to about 4 to 5 million SNPs in an individual’s genome. Scientists have found more than 600 million SNPs in populations around the world. The combination of technical feasibility, scientific reliability, and analytical power makes SNPs the optimal choice for autosomal DNA testing in genealogical and ancestry applications. [30]

Ancestry information markers refers to locations in the genome that have varied sequences at that location and the relative abundance of those markers differs based on the continent from which individuals can trace their ancestry. So by using a series of these ancestry information markers, sometimes 20 or 30 more, and genotyping an individual you can determine from the frequency of those markers where their great, great, great, great ancestors may have come from. [31]

SNPs represent natural variations that make individuals unique while being common enough to be reliable DNA test markers. Their high frequency makes them ideal markers for genetic analysis. The vast majority of SNPs have no effect on health or development. SNPs are generally found in the DNA between genes rather than within genes themselves. [32]

While other genetic markers exist, SNPs are preferred ancestry information markers. SNPs are used for genetic testing based on their reliability and accuracy. SNPs are stable genetic markers that are passed down through generations. SNPs offer more detailed information about both recent and ancient ancestry. They also allow for fairly precise ethnic profiling and ancestral location inference.[33]

How atDNA Tests Figure Out Genetic Relationships

In a “Nutshell”: How do DNA companies Figure Out Genetic Relationships

Analyzing SNPs: DNA companies analyze hundreds of thousands of single nucleotide polymorphisms (SNPs) across the 22 autosomal chromosomes. [34]

The results from different atDNA test companies can vary. The variance is based on a number of factors. All major DNA testing companies use equipment that analyze DNA specimens with what are called ‘chips’ that use DNA microarray technology supplied by a company named Illumina. However, different companies use different versions of the Illumina chip and each version tests different sets of SNP (Single Nucleotide Polymorphism) locations.

Illustration Ten: How DNA Microarray Technology Analyzes Autosomal DNA

Source: Bergström, Ann-Louise and Lasse Folkersen , DNA microarray, 15 May 2020, Moving Science, https://movingscience.dk/dna-microarray/

Companies can specify their own “other” locations to be included on their chip. The number of markers tested varies significantly by company. FamilyTreeDNA uses a customized Illumina chip. 23andMe and AncestryDNA use a customized Illumina Global Screening Array (GSA) chip. Living DNA uses an Affymetrix Axiom microarray (Sirius) chip. My Heritage uses an Illumina GSA chip. [35]

Illustration of Illumina Microarray Chips

Source: Web Graphic Array with GE Inserts, Illumina, Powerfully Informative Microarrays, Illumina,https://www.illumina.com/techniques/microarrays.html

“Each DNA testing company purchases DNA processing equipment. Illumina is the big dog in this arena. Illumina defines the capacity and structure of each chip. In part, how the testing companies use that capacity, or space on each chip, is up to each company. This means that the different testing companies test many of the same autosomal DNA SNP locations, but not all of the same locations. … This means that each testing company includes and reports many of the same, but also some different SNP locations when they scan your DNA. …  In addition to dealing with different file formats and contents from multiple DNA vendors, companies change their own chips and file structure from time to time. In some cases, it’s a forced change by the chip manufacturer. Other times, the vendors want to include different locations or make improvements.” [36]

When DNA companies change DNA chips, a different version of the company’s own file may contain different positions. DNA testing companies have to “fill in the blanks” for compatibility, and they do this using a technique called imputation. Illumina forced their customers to adopt imputation in 2017 when they dropped the capacity of their chip. [37]

Identify Matching Segments: The DNA test software for respective DNA companies compare the SNP data between two individuals to identify segments of DNA that appear to be identical or similar. These matching DNA segments indicate the likelihood of DNA inherited from a common ancestor. [38]

The ability to identify DNA matches between individuals is largely influenced by the size of database tests and the SNPs that were sampled to atDNA tests. As indicated, there are main differences between atDNA tests from various companies (e.g. 23andMe, Ancestry.com, FamilyTree DNA, LivingDNA, MyHeritage) regarding SNPs that are tested and the relative size of their respective database results.

Each company maintains its own proprietary reference databases and matching algorithms. As indicated in table three below, AncestryDNA has a larger customer database (over 20 million) compared to 23andMe (about 12 million). This gives AncestryDNA an advantage for finding genetic relatives.

Table Three: Data Base Size and Number of SNPs Tested by DNA Company in 2024

DNA
Company
Data Base Size of
atDNA Test Results
No. of Autosome
SNPs Tested
23andMe14 Million630,`132
FamilyTreeDNA1.7 million612,272
AncestryDNA25 million637,639
My Heritage8.5 million576,157
Living DNA300,000683,503
Source: Autosomal DNA testing comparison chart, International Society of Genetic Genalogy Wiki, This page was last edited on 8 October 2024, https://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart

Measuring Segment Length: The length of matching segments of SNPs is measured in centimorgans (cM). Centimorgans measure the likelihood of genetic recombination between two markers on a chromosome. One centimorgan represents a one percent chance that two genetic markers will be separated by a recombination event in a single generation. This measurement helps geneticists and genealogists estimate how close two individuals are genetically related. [39]

Centimorgans (cM) are a crucial unit of measurement in genetic atDNA testing. It is used to quantify genetic distance and determine relationships between individuals based on shared DNA. The more centimorgans two people share, the more likely they are related. in addition to the number of cMs shared, longer segments generally indicate a closer relationship.

One cM corresponds on the average to about 1 million base pairs in humans. The total human genome is approximately 7400 cM long. A parent-child relationship typically shares about 3400-3700 cM. More distant relatives share fewer cMs. However, there can be overlap in cM ranges for different relationship types, so additional genealogical research is often needed to determine exact relationships.

(A centiMorgan) is less of a physical distance and more of a measurement of probability. It refers to the DNA segments that you have in common with others and the likelihood of sharing genetic traits. The ends of shared segments are defined by points where DNA swapped between two chromosomes, and the centimorgan is a measure of the probability of getting a segment that large when these swaps occur.” [40]

Chart One: Ranges of Shared centiMorgans with Family

Click for Larger View | Source: Bettinger, Blaine, Version 4.0! March 2020 Update to the Shared cM Project!, 27 Mar 2020, The Genetic Genealogist, https://thegeneticgenealogist.com/2020/03/27/version-4-0-march-2020-update-to-the-shared-cm-project/

When you take an atDNA test, the testing company compares your DNA to others in their database. The amount of DNA you share with a match is reported in centimorgans. Generally, the more centimorgans you share with someone, the more closely you are related to this other person. Shared centimorgan ranges can often indicate how many generations separate two people. Certain shared cM values can also suggest possible half-sibling or half-first cousin relationships as opposed to full relatives.

Calculating Total Shared DNA: The total amount of shared DNA is calculated by summing up the lengths of all matching segments, typically expressed in cMs or as a percentage of the total amount of shared SNPs sampled. [41]

Applying Thresholds: Each company sets minimum thresholds for segment length and total shared DNA to be considered a match. For example, FamilyTree DNA requires at least one segment of 9 cM or more.

Table Four: Different cM Thresholds for atDNA Matches Across DNA Companies

DNA CompanyCriteria for matching segments
23andMe9 cMs and at least 700 SNPs for one half-identical region

5 cMs and 700 SNPs with at least two half-identical regions being shared
FamilyTreeDNAAll matching segments must be at least 6 cMs in length. almost all matching segments contain at least 800 SNPs & all matching segments contain at least 600 SNPs.
AncestryDNA6 cMs per segment before the Timber algorithm is applied and a total of at least 8 cMs after Timber is applied.
My Heritage8 cM for the first matching segment and at least 6 cMs for the 2nd matching segment; 12 cM for the first matching segment in people whose ancestry is at least 50% Ashkenazi Jewish
Living DNA9.46 cMs for the first segment
Source: Autosomal DNA testing comparison chart, International Society of Genetic Genalogy Wiki, This page was last edited on 8 October 2024, https://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart

Relationship Prediction: The amount of shared DNA is compared to expected ranges for different relationships to predict how two people may be related. Close relationships like parent/child or full siblings have very distinct amounts of shared DNA, while more distant relationships have overlapping ranges. [42]

Special Considerations: Some of the DNA companies use phasing algorithms to improve accuracy, especially for analyzing smaller shared segments. Some also apply special algorithms for populations with higher rates of endogamy, like Ashkenazi Jews. [43]

Moving Onward

I imagine all of this makes total sense. I, however, believe, all of this is totally confusing. To walk away with some semblance of understanding, I would focus on the following observations:

  • DNA tests can only provide so much information. Traditional genealogical research brings atDNA results into focus. Genetic and traditional research strategies can work hand in hand.
  • atDNA tests have the ability to trace living genetic relatives on both sides of your family tree. However, their effectiveness is limited in terms of how many generations back they can effectively provide results.
  • While autosomal DNA testing has become increasingly accurate, there are still limitations in the context of estimating genetic relations and finding relatives.
  • When looking at atDNA matches, centimorgans (cM) are the key unit of measurement in genetic atDNA testing. It is used to determine relationships between individuals based on shared DNA. The more centimorgans two people share, the more likely they are related. in addition to the number of cMs shared, longer segments generally indicate a closer relationship.

Sources

Feature image: The image depicts a branch from a massive family tree that shows 6,000 relatives spanning seven generations.  It is part of a study that links 13 million people related by genetics or marriage.  Source: Jocelyn Kaiser, Thirteen million degrees of Kevin Bacon: World’s largest family tree shines light on life span, who marries whom, Science, 1 Mar 2018, https://www.science.org/content/article/thirteen-million-degrees-kevin-bacon-world-s-largest-family-tree-shines-light-life-span .

See the original study behind this effort at: Kaplanis J, Gordon A, Shor T, Weissbrod O, Geiger D, Wahl M, Gershovits M, Markus B, Sheikh M, Gymrek M, Bhatia G, MacArthur DG, Price AL, Erlich Y. Quantitative analysis of population-scale family trees with millions of relatives. Science. 2018 Apr 13;360(6385):171-175. doi: 10.1126/science.aam9309. Epub 2018 Mar 1. PMID: 29496957; PMCID: PMC6593158. https://pmc.ncbi.nlm.nih.gov/articles/PMC6593158/

[1] See the following stories:

[2] Bettinger, Blaine, Everyone Has Two Family Trees – A Genealogical Tree and a Genetic Tree, 10 Nov 2009, The Genetic Genealogist, https://thegeneticgenealogist.com/2009/11/10/qa-everyone-has-two-family-trees-a-genealogical-tree-and-a-genetic-tree/

Understanding genetic ancestry testing, International Society of Genetic Genealogy Wiki, This page was last edited on on 25 August 2015, https://isogg.org/wiki/Understanding_genetic_ancestry_testing

[3] Human Y-chromosome DNA haplogroup, Wikipedia, This page was last edited on 5 October 2024,, https://en.wikipedia.org/wiki/Human_Y-chromosome_DNA_haplogroup

Human mitochondrial DNA haplogroup, Wikipedia, This page was last edited on 5 October 2024, https://en.wikipedia.org/wiki/Human_mitochondrial_DNA_haplogroup

Rowe, Katy, Genealogy’s Secret Weapon: How Using mtDNA Can Solve Family Mysteries, 10 May 2023, FamilyTreeDNA Blog, https://blog.familytreedna.com/mtdna/

MtDNA testing comparison chart, International Society of Genetic Genealogy Wiki, This page was last edited on 3 September 2023, https://isogg.org/wiki/MtDNA_testing_comparison_chart

Y chromosome DNA tests, International Society of Genetic Genealogy Wiki, This page was last edited on 6 September 2024, https://isogg.org/wiki/Y_chromosome_DNA_tests

Y-DNA STR testing comparison chart, International Society of Genetic Genealogy Wiki, This page was last edited on 11 July 2022, https://isogg.org/wiki/Y-DNA_STR_testing_comparison_chart

Balding, David, Debbie Kennett and Mark Thomas, Understanding genetic ancestry testing, This page was last edited on 25 August 2015, Iternational Society of Genetic Genealogy Wiki, https://isogg.org/wiki/Understanding_genetic_ancestry_testing

Rowe-Schurwanz, Kathy, Using mtDNA for Genealogical Research, Aug 14, 2024, FamilyTreeDNA Blog, https://blog.familytreedna.com/using-mtdna-genealogical-research/

Rowe-Schurwanz, Kathy, How Autosomal DNA Testing Works, June10, 2024, FamilyTreeDNA Blog, https://blog.familytreedna.com/how-autosomal-dna-testing-works/

Unveiling the Power of Big Y-700: Unraveling the Journey and Advantages, Oct 21, 2022, FamilyTreeDNA Blog, https://blog.familytreedna.com/big-y-700/

Mitochondrial Eve, Wikipedia, This page was last edited on 18 September 2024, https://en.wikipedia.org/wiki/Mitochondrial_Eve

Y-chromosomal Adam, Wikipedia, This page was last edited on 19 September 2024, https://en.wikipedia.org/wiki/Y-chromosomal_Adam

[4] Newton, Maud, America’s Ancestry Craze: Making sense of our family-tree obsession, June 2014, Harper’s Magazine, https://harpers.org/archive/2014/06/americas-ancestry-craze/

[5] Jorde LB, Bamshad MJ. Genetic Ancestry Testing: What Is It and Why Is It Important? JAMA. 2020 Mar 17;323(11):1089-1090. doi:10.1001/jama.2020.0517 PMID: 32058561; PMCID: PMC8202415 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8202415/

[6] Antonio Regalodo, More than 26 million people have taken an at-home ancestry test, MIT Technology Review, 11 Feb 2019, https://www.technologyreview.com/2019/02/11/103446/more-than-26-million-people-have-taken-an-at-home-ancestry-test/

Covering Your Bases: Introduction to Autosomal DNA Coverage, Legacy Tree Genealogists, https://www.legacytree.com/blog/introduction-autosomal-dna-coverage

DNA Geek, Family DNA Tests for Ancestry & Genealogy, Navigating the World of DNA,

[7] Has the consumer DNA test boom gone bust?, Feb 20, 2020, updated Jul 28, 2024, Advisory Board, https://www.advisory.com/daily-briefing/2020/02/20/dna-tests 

[8] Ibid

[9] Krimsky Sheldon, The Business of DNA Ancestry, in: Understanding DNA Ancestry. Understanding Life. Cambridge University Press; 2021, Pages 8-16.

Molla, Rami, Why DNA tests are suddenly unpopular, 13 Feb 2020, Vox, https://www.vox.com/recode/2020/2/13/21129177/consumer-dna-tests-23andme-ancestry-sales-decline#

Spiers, Caroline, Keeping It in the Family: Direct-to-Consumer Genetic Testing and the Fourth Amendment, Houston Law Review, Vol 59, Issue 5, May 23 2020, https://houstonlawreview.org/article/36547-keeping-it-in-the-family-direct-to-consumer-genetic-testing-and-the-fourth-amendment

Has the consumer DNA test boom gone bust?, Updated 28 Jul 2023, Advisory Board, https://www.advisory.com/daily-briefing/2020/02/20/dna-tests

Linder, Emmett, As 23andMe Struggles, Concerns Surface About Its Genetic Data, 5 Oct 2024, New York Times, https://www.nytimes.com/2024/10/05/business/23andme-dna-bankrupt.html

Estes, Roberta, DNA Testing Sales Decline: Reason and Reasons, 11 Feb 2020, DNAeXplained – Genetic Genealogy Blog, https://dna-explained.com/2020/02/11/dna-testing-sales-decline-reason-and-reasons/

[10] Fish, Eric, The Sordid Saga of 23andMe, 21 Oct 2024, All Science Great & Small, https://allscience.substack.com/p/the-sordid-saga-of-23andme

Prictor, Megan, Millions of People’s DNA in Doubt as 23andMe Faces Bankruptcy, 21 Oct 2024, Science Alert, https://www.sciencealert.com/millions-of-peoples-dna-in-doubt-as-23andme-faces-bankruptcy

Linder, Emmett, As 23andMe Struggles, Concerns Surface About Its Genetic Data, 5 Oct 2024, New York Times, https://www.nytimes.com/2024/10/05/business/23andme-dna-bankrupt.html

Allyn, Bobby, 23andMe is on the brink. What happens to all its DNA data?, NPR, https://www.npr.org/2024/10/03/g-s1-25795/23andme-data-genetic-dna-privacy

23andMe Facing Bankruptcy, FoxLocal 26, , https://youtu.be/ZfBOCxbWAeY

[10a] Estes, Roberta, 23andMe Trouble – Step-by-Step Instructions to Preserve Your Data and Matches, 19 Sep 2024, DNAeXplained – Genetic Genealogy, https://dna-explained.com/2024/09/19/23andme-trouble-step-by-step-instructions-to-preserve-your-data-and-matches/

[11] A karyotype is a visual representation of an individual’s complete set of chromosomes, displaying their number, size, and structure, typically arranged in pairs and ordered by size.

“A karyotype is the general appearance of the complete set of chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. … A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are generally organized in pairs, ordered by size and position of centromere for chromosomes of the same size.”

Karotype, Wikipedia, This page was last edited on 12 September 2024, https://en.wikipedia.org/wiki/Karyotype

Karyotype, Wikipedia, This page was last edited on 17 October 2024,, https://en.wikipedia.org/wiki/Karyotype

Dutra, Ameria, Karyotype, National Genome Human Genome Research Institute, https://www.genome.gov/genetics-glossary/Karyotype

Karyotype, ScienceDirect, definition and discussion is from from Antonie D. Kline and Ethylin Wang Jabs, eds., Genomics in the Clinic,  2024, Shen Gu, Bo Yuan, Ethylin Wang Jabs, Christine M. Eng , Chapter 2 – Basic Principles of Genetics and Genomics,  Pages 5-28 ,  https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/karyotype 

Shen Gu, Bo Yuan, Ethylin Wang Jabs, Christine M. Eng, Chapter 2 – Basic Principles of Genetics and Genomics, Editor(s): Antonie D. Kline, Ethylin Wang Jabs, Genomics in the Clinic, Academic Press, 2024, Pages 5-28

[12] Autosomes are the non-sex chromosomes found in the cells of organisms. Autosomes are any chromosomes that are not sex chromosomes (allosomes). In humans, there are 22 pairs of autosomes, numbered from 1 to 22. They come in identical pairs in both males and females. They are numbered based on size, shape, and other properties. They contain genes that control the inheritance of all traits except sex-linked ones.

[13] Recombination is a process by which pieces of DNA are broken and recombined to produce new combinations of nucleotides or alleles. Recombination primarily happens between homologous chromosomes, which are paired chromosomes with similar genetic information, allowing for the exchange of corresponding DNA segments.

During meiosis, when homologous chromosomes pair up, a process called “crossing over” occurs where DNA strands break and rejoin, swapping genetic material between the chromosomes. This recombination process creates genetic diversity at the level of genes that reflects differences in the DNA sequences of different organisms. 

Recombination, Scitable by nature Education, Nature, 2014, https://www.nature.com/scitable/definition/recombination-226/

Genetic recombination, Wikipedia, This page was last edited on 5 October 2024, https://en.wikipedia.org/wiki/Genetic_recombination

Alberts B, Johnson A, Lewis J, et al., General Recombination, in The cell, New York: Garland Science; 2002. https://www.ncbi.nlm.nih.gov/books/NBK26898/

[14] Autosomal DNA Statistics, International Society of Genetic Genealogy Wiki, Page was last edited 4 August 2022, Page accessed 14 Aug 2022, https://isogg.org/wiki/Autosomal_DNA_statistics

Nicole Dyer, Charts for Understanding DNA Inheritance, 14 Aug 2019, Family Locket, Page accessed 10 Oct 2021, https://familylocket.com/charts-for-understanding-dna-inheritance/

[15] Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for sexual reproduction.

Meiosis, 2014, Scitable by Nature Education, Nature, https://www.nature.com/scitable/definition/meiosis-88/

Gilchrist, Daniel, Meiosis, National Human Genome Research Institute, https://www.genome.gov/genetics-glossary/Meiosis

Meiosis, Wikipedia, This page was last edited on 22 August 2024, https://en.wikipedia.org/wiki/Meiosis

[16] What are reduced penetrance and variable expressivity?, MedlinePlus, https://medlineplus.gov/genetics/understanding/inheritance/penetranceexpressivity/

Miko, Iiona,  Phenotype variability: penetrance and expressivity. Nature Education 1(1):137 , 2008, https://www.nature.com/scitable/topicpage/phenotype-variability-penetrance-and-expressivity-573/

Expressivity (genetics), Wikipedia, This page was last edited on 9 October 2024, https://en.wikipedia.org/wiki/Expressivity_(genetics)

[17] Average Percent DNA Shared Between Relatives, 23andMe Customer Care, Tools, 23andMe, https://customercare.23andme.com/hc/en-us/articles/212170668-Average-Percent-DNA-Shared-Between-Relatives

Autosomal Statistics, International Society of Genetic Genealogy Wiki, This page was last edited on 17 October 2022, https://isogg.org/wiki/Autosomal_DNA_statistics

[18] The genome is the entire set of DNA instructions found in a cell. In humans, the genome consists of 23 pairs of chromosomes located in the cell’s nucleus, as well as a small chromosome in the cell’s mitochondria. A genome contains all the information needed for an individual to develop and function.

Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

[19] Fundamental Concepts of Genetics and about the Human Genome, Eupedia, page accessed 3 Feb 2021, https://www.eupedia.com/genetics/human_genome_and_genetics.shtml

Sheldon Krimsky, Understanding DNA Ancestry, Cambridge: Cambridge University , 2022, Page 18

Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

[20] Nucleotide, National Cancer Institute, https://www.cancer.gov/publications/dictionaries/genetics-dictionary/def/nucleotide

Nucleotide, Wikipedia, This page was last edited on 3 September 2024, https://en.wikipedia.org/wiki/Nucleotide

Brody, Lawrence, Nucleotide, National Human Genome Research Institute, 1 Nov 2024, https://www.genome.gov/genetics-glossary/Nucleotide 

[21] Non-Coding DNA, AncestryDNA Learning Hub, 16 Aug 2016, https://www.ancestry.com/c/dna-learning-hub/non-coding-dna

What is Noncoding DNA?, MedlinePlus, https://medlineplus.gov/genetics/understanding/basics/noncodingdna/

[22] Non-Coding DNA, AncestryDNA Learning Hub, https://www.ancestry.com/c/dna-learning-hub/junk-dna

Ohno, Susumu. “So Much ‘Junk’ DNA in Our Genome.” Brookhaven Symposium on Biology, Volume 23, 1972: 366-370.

Zhang F, Lupski JR. Non-coding genetic variants in human disease. Hum Mol Genet. 2015 Oct 15;24(R1):R102-10. doi: 10.1093/hmg/ddv259. Epub 2015 Jul 7. PMID: 26152199; PMCID: PMC4572001 https://pmc.ncbi.nlm.nih.gov/articles/PMC4572001/

Peña-Martínez EG, Rodríguez-Martínez JA. Decoding Non-coding Variants: Recent Approaches to Studying Their Role in Gene Regulation and Human Diseases. Front Biosci (Schol Ed). 2024 Mar 1;16(1):4. doi: 10.31083/j.fbs1601004. PMID: 38538340; PMCID: PMC11044903 https://pmc.ncbi.nlm.nih.gov/articles/PMC11044903/

Malte Spielmann, Stefan Mundlos, Looking beyond the genes: the role of non-coding variants in human disease, Human Molecular Genetics, Volume 25, Issue R2, 1 October 2016, Pages R157–R165, https://doi.org/10.1093/hmg/ddw205

Vitsios, D., Dhindsa, R.S., Middleton, L. et al. Prioritizing non-coding regions based on human genomic constraint and sequence context with deep learning. Nat Commun 12, 1504 (2021). https://doi.org/10.1038/s41467-021-21790-4

Ellingford, J.M., Ahn, J.W., Bagnall, R.D. et al. Recommendations for clinical interpretation of variants found in non-coding regions of the genome. Genome Med 14, 73 (2022). https://doi.org/10.1186/s13073-022-01073-3

[23]  The 1000 Genomes Project Consortium. A global reference for human genetic variation. Nature 526, 68–74 (2015). https://doi.org/10.1038/nature15393https://www.nature.com/articles/nature15393#citeas

Human Genomic Variation, National Human Genome Research Institute, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

For the 99.9 percent figure, see for example: Krimsky, Sheldon, Understanding DNA Ancestry, Cambridge, Cambridge University Press, 2022, Page 18

[22] Zou H, Wu LX, Tan L, Shang FF, Zhou HH. Significance of Single-Nucleotide Variants in Long Intergenic Non-protein Coding RNAs. Front Cell Dev Biol. 2020 May 25;8:347. doi: 10.3389/fcell.2020.00347. PMID: 32523949; PMCID: PMC7261909

The Order of Nucleotides in a Gene Is Revealed by DNA Sequencing, Scitable, Nature Education, https://www.nature.com/scitable/topicpage/the-order-of-nucleotides-in-a-gene-6525806/

single nucleotide variant, National Cancer Institute, https://www.cancer.gov/publications/dictionaries/genetics-dictionary/def/single-nucleotide-variant

Wright, A.F. (2005). Genetic Variation: Polymorphisms and Mutations. In eLS, (Ed.). https://doi.org/10.1038/npg.els.0005005

Single-nucleotide polymorphism, Wikipedia, This page was last edited on 29 September 2024, https://en.wikipedia.org/wiki/Single-nucleotide_polymorphism

SNVs vs. SNPs, CD Genomics, https://www.cd-genomics.com/resource-snvs-vs-snps.html

[23] Human Genomic Variation, Fact Sheet, National Human Genome Research Institute, 1 Feb 2023, https://www.genome.gov/about-genomics/educational-resources/fact-sheets/human-genomic-variation

[24] Ichikawa, K., Kawahara, R., Asano, T. et al. A landscape of complex tandem repeats within individual human genomes. Nat Commun 14, 5530 (2023). https://doi.org/10.1038/s41467-023-41262-1 

Tandem Repeat, Wikipedia, This page was last edited on 12 July 2024, https://en.wikipedia.org/wiki/Tandem_repeat

Myers, P., Tandem repeats and morphological variation. Nature Education 1(1):1, 2007,  http://scienceblogs.com/pharyngula/2007/10/tandem_repeats_and_morphologic.php

Usdin K. The biological effects of simple tandem repeats: lessons from the repeat expansion diseases. Genome Res. 2008 Jul;18(7):1011-9. doi: 10.1101/gr.070409.107. PMID: 18593815; PMCID: PMC3960014. https://pmc.ncbi.nlm.nih.gov/articles/PMC3960014/

Ichikawa, K., Kawahara, R., Asano, T. et al. A landscape of complex tandem repeats within individual human genomes. Nat Commun 14, 5530 (2023). https://doi.org/10.1038/s41467-023-41262-1 

Mitsuhashi, S., Frith, M.C., Mizuguchi, T. et al. Tandem-genotypes: robust detection of tandem repeat expansions from long DNA reads. Genome Biol 20, 58 (2019). https://doi.org/10.1186/s13059-019-1667-6 

Sequencing 101: Tandem repeats, 22 Nov 2023, PacBio, https://www.pacb.com/blog/sequencing-101-tandem-repeats/

Kai Zhou, Abram Aertsen, Chris W. Michiels, The role of variable DNA tandem repeats in bacterial adaptation, FEMS Microbiology Reviews, Volume 38, Issue 1, January 2014, Pages 119–141, https://doi.org/10.1111/1574-6976.12036

Fan H, Chu JY. A brief review of short tandem repeat mutation. Genomics Proteomics Bioinformatics. 2007 Feb;5(1):7-14. doi: 10.1016/S1672-0229(07)60009-6. PMID: 17572359; PMCID: PMC5054066. https://pmc.ncbi.nlm.nih.gov/articles/PMC5054066/

[25] Structural variation, Wikipedia, This page was last edited on 30 August 2024, https://en.wikipedia.org/wiki/Structural_variation

Scott AJ, Chiang C, Hall IM. Structural variants are a major source of gene expression differences in humans and often affect multiple nearby genes. Genome Res. 2021 Dec;31(12):2249-2257. doi: 10.1101/gr.275488.121. Epub 2021 Sep 20. PMID: 34544830; PMCID: PMC8647827 https://pmc.ncbi.nlm.nih.gov/articles/PMC8647827/

Feuk, L., Carson, A. & Scherer, S. Structural variation in the human genome. Nat Rev Genet 7, 85–97 (2006). https://doi.org/10.1038/nrg1767 

[26] CNVs are typically defined as DNA segments that are: larger than 1,000 base pairs (1 kilobase); usually less than 5 megabases in length; and  can include both duplications (additional copies) and deletions (losses) of genetic material. 

CNVs are remarkably common in human genomes. They account for approximately 5 to 9.5% of the human genome. They affect more base pairs than other forms of mutation when comparing two human genomes. They play crucial roles in evolution, population diversity, and disease development. 

Copy number variation, Wikipedia, This page was last edited on 24 September 2024, https://en.wikipedia.org/wiki/Copy_number_variation

Pös O, Radvanszky J, Buglyó G, Pös Z, Rusnakova D, Nagy B, Szemes T. DNA copy number variation: Main characteristics, evolutionary significance, and pathological aspects. Biomed J. 2021 Oct;44(5):548-559. doi: 10.1016/j.bj.2021.02.003. Epub 2021 Feb 13. PMID: 34649833; PMCID: PMC8640565 https://pmc.ncbi.nlm.nih.gov/articles/PMC8640565/

Eichler, E. E. Copy Number Variation and Human Disease. Nature Education 1(3):1, 2008,  https://www.nature.com/scitable/topicpage/copy-number-variation-and-human-disease-741737/

What are copy number variants?, 12 Aug 2020, Genomics Education Programme, https://www.genomicseducation.hee.nhs.uk/blog/what-are-copy-number-variants/

Clancy, S. Copy number variation. Nature Education 1(1):95, 2008, https://www.nature.com/scitable/topicpage/copy-number-variation-445/

Copy number variant, National Cancer Institute, https://www.cancer.gov/publications/dictionaries/genetics-dictionary/def/copy-number-variant

Copy Number Variation (CNV), 3 Nov 2024, National Human Genome Research Institute, https://www.genome.gov/genetics-glossary/Copy-Number-Variation

[29] Several approaches are used to determine if an SNV meets the one percent population frequency threshold:

  • Large-Scale Population Studies: Projects like the 1000 Genomes Project have sequenced thousands of individuals across multiple populations to identify and validate SNPs
  • A number of detection technologies are used such as real-time PCR, the use of microarrays, and Next-generation sequencing (NGS).

See for example:

The 1000 Genomes Project Consortium. A global reference for human genetic variation. Nature 526, 68–74 (2015). https://doi.org/10.1038/nature15393 

Patricia M Schnepp, Mengjie Chen, Evan T Keller, Xiang Zhou, SNV identification from single-cell RNA sequencing data, Human Molecular Genetics, Volume 28, Issue 21, 1 November 2019, Pages 3569–3583, https://doi.org/10.1093/hmg/ddz207

Telenti A, Pierce LC, Biggs WH, di Iulio J, Wong EH, Fabani MM, Kirkness EF, Moustafa A, Shah N, Xie C, Brewerton SC, Bulsara N, Garner C, Metzker G, Sandoval E, Perkins BA, Och FJ, Turpaz Y, Venter JC. Deep sequencing of 10,000 human genomes. Proc Natl Acad Sci U S A. 2016 Oct 18;113(42):11901-11906. doi: 10.1073/pnas.1613365113. Epub 2016 Oct 4. PMID: 27702888; PMCID: PMC5081584. https://pmc.ncbi.nlm.nih.gov/articles/PMC5081584/

SNVs vs. SNPs, CD Genomics, https://www.cd-genomics.com/resource-snvs-vs-snps.html

Efficiently detect single nucleotide polymorphisms and variants, Illumina, https://www.illumina.com/techniques/popular-applications/genotyping/snp-snv-genotyping.html

[30] What are single nucleotide polymorphisms (SNPs)?, MedlinePlus, https://medlineplus.gov/genetics/understanding/genomicresearch/snp/

SNP, IMS Riken Center for Integrative Medical Sciences, https://www.ims.riken.jp/english/glossary/genome.php

The 1000 Genomes Project Consortium. A global reference for human genetic variation.Nature 526, 68–74 (2015). https://doi.org/10.1038/nature15393

[31] Ancestry Information Markers, National Human Genome Research Institute, https://www.genome.gov/genetics-glossary/Ancestry-informative-Markers

Joon-Ho You, Janelle S. Taylor, Karen L. Edwards, Stephanie M. Fullerton, What are our AIMs? Interdisciplinary Perspectives on the Use of Ancestry Estimation in Disease Research, National Library of Medicine, 2012 Nov 5. doi: 10.1080/21507716.2012.717339

Huckins, L., Boraska, V., Franklin, C. et al. Using ancestry-informative markers to identify fine structure across 15 populations of European origin. Eur J Hum Genet 22, 1190–1200 (2014). https://doi.org/10.1038/ejhg.2014.1

[32] What are single nucleotide polymorphisms (SNPs)?, MedlinePlus, https://medlineplus.gov/genetics/understanding/genomicresearch/snp/

[33] AIMs are single-nucleotide polymorphisms (SNPs) that show substantially different frequencies between populations from different geographical regions15. These genetic variations can be used to estimate the geographical origins of a person’s ancestors, typically by continent of origin.

AIMs are found within the approximately 15 million SNP sites in human DNA (about 0.4% of total base pairs). They are often traced to the Y chromosome, Mitochondrial DNA, and Autosomal regions.

AIMs can distinguish between major continental populations (Africa, Asia, Europe). They require multiple markers working together (typically 20-30 or more) for accurate ancestry determination. They can identify fine population structure within continents using larger marker sets. 

The effectiveness of AIMs depends on the number of markers used:

  • 40-80 markers can identify five broad continental clusters;
  • 128 markers can characterize samples into 8 broad continental groups; and
  • Larger sets (>46,000 markers) can identify detailed subpopulation structure

Hinkley, Ellen, DNA Testing Choice, 16 Dec 2016, https://dnatestingchoice.com/en-us/news/what-is-an-autosomal-dna-test

Lamiaa Mekhfi, Bouchra El Khalfi, Rachid Saile, Hakima Yahia, and Abdelaziz Soukri, The interest of informative ancestry markers (AIM) and their fields of application, , BIO Web of Conferences 115, 07003 (2024),https://doi.org/10.1051/bioconf/202411507003 

Huckins, L., Boraska, V., Franklin, C. et al. Using ancestry-informative markers to identify fine structure across 15 populations of European origin. Eur J Hum Genet 22, 1190–1200 (2014). https://doi.org/10.1038/ejhg.2014.1 

Ancestry Information Markers, National Human Genome Research Institute, https://www.genome.gov/genetics-glossary/Ancestry-informative-Markers

Ancestry-informative marker, Wikipedia, This page was last edited on 14 August 2024, https://en.wikipedia.org/wiki/Ancestry-informative_marker

[34] Autosomal DNA Statistics, International Society of Genetic Genealogy Wiki, This page was last edited on 17 October 2022, https://isogg.org/wiki/Autosomal_DNA_statistics

Autosomal SNP comparison chart, International Society of Genetic Genealogy Wiki, This page was last edited on 29 January 2024, https://isogg.org/wiki/Autosomal_SNP_comparison_chart

DNA Structure and the Testing Process, FamilyTreeDNA Help Center, https://help.familytreedna.com/hc/en-us/articles/6189190247311-DNA-Structure-and-the-Testing-Process

Catherine A. Ball, Mathew J Barber, Jake Byrnes, Peter Carbonetto, Kenneth G. Chahine, Ross E. Curtis, Julie M. Granka, Eunjung Han, Eurie L. Hong, Amir R. Kermany, Natalie M. Myres, Keith Noto, Jianlong Qi, Kristin Rand, Yong Wang and Lindsay Willmore, AncestryDNA Matching White Paper, 31 Mar 2016, AncestryDNA, https://www.ancestry.com/cs/dna-help/matches/whitepaper; PDF: https://www.ancestry.com/dna/resource/whitePaper/AncestryDNA-Matching-White-Paper.pdf

Autosomal DNA match thresholds, International Society of Genetic Genealogy Wiki, This page was last edited on 31 August 2024, https://isogg.org/wiki/Autosomal_DNA_match_thresholds

Daniel Kling, Christopher Phillips, Debbie Kennett, Andreas Tillmar,

Investigative genetic genealogy: Current methods, knowledge and practice, Forensic Science International: Genetics, Volume 52, 2021, https://doi.org/10.1016/j.fsigen.2021.102474

Davis DJ, Challis JH. Automatic segment filtering procedure for processing non-stationary signals. J Biomech. 2020 Mar 5;101:109619. doi: 10.1016/j.jbiomech.2020.109619. Epub 2020 Jan 9. PMID: 31952818.

The Order of Nucleotides in a Gene Is Revealed by DNA Sequencing, Scitable, Nature Education, https://www.nature.com/scitable/topicpage/the-order-of-nucleotides-in-a-gene-6525806/

[35] The Illumina Global Screening Array (GSA) is a customizable genotyping microarray platform.  Its base configuration

  • Contains approximately 654,000 fixed markers spanning the human genome;
  • Supports 24 samples per array in standard format;
  • Requires 200 ng DNA input;
  • Achieves call rates greater than 99% and reproducibility greater than 99.9%; and
  • Allows addition of up to 100,000 custom markers

Illumina microarray solutions, Illumina, https://www.illumina.com/techniques/microarrays.html

Efficiently detect single nucleotide polymorphisms and variants, Illumina, https://www.illumina.com/techniques/popular-applications/genotyping/snp-snv-genotyping.html

Custom design tools for genotyping any variant, in any species, Illumina, https://www.illumina.com/techniques/popular-applications/genotyping/custom-genotyping.html

Infinium™ Global Screening Array-24 v3.0 BeadChip, Illumina , https://www.illumina.com/content/dam/illumina-marketing/documents/products/datasheets/infinium-global-screening-array-data-sheet-370-2016-016.pdf

Infinium Global Screening Array-24 Kit, Illumina, https://www.illumina.com/products/by-type/microarray-kits/infinium-global-screening.html

Efficiently detect single nucleotide polymorphisms and variants, Illumina, https://www.illumina.com/techniques/popular-applications/genotyping/snp-snv-genotyping.html

Custom design tools for genotyping any variant, in any species, Illumina, https://www.illumina.com/techniques/popular-applications/genotyping/custom-genotyping.html

[36] Estes, Roberta, Comparing DNA Results – Different Tests at the Same Testing Company, 5 Sep 2017, DNAeXplained – Genetic Genealogy, https://dna-explained.com/2023/05/18/comparing-dna-results-different-tests-at-the-same-testing-company/

[37]  Estes, Roberta, Concepts -Imputation, 5 Sep 2017, DNAeXplained – Genetic Genealogy, https://dna-explained.com/2017/09/05/concepts-imputation/

Illumina microarray solutions, Illumina, https://www.illumina.com/techniques/microarrays.html

Efficiently detect single nucleotide polymorphisms and variants, Illumina, https://www.illumina.com/techniques/popular-applications/genotyping/snp-snv-genotyping.html

[38] See for example: Our Autosomal DNA Test (Family Finder™), FamilyTreeDNA HelpCenter, https://help.familytreedna.com/hc/en-us/articles/4411203169679-Our-Autosomal-DNA-Test-Family-Finder

[39] Different DNA testing companies use centimorgans (cM) in slightly different ways when reporting matches and relationships:

  1. Matching thresholds: Companies set different minimum thresholds for reporting matches. For example: AncestryDNA currently uses a threshold of 8 cM; 23andMe uses 7 cM and at least 700 SNPs for the first matching segment; and MyHeritage uses 8 cM.
  2. Algorithms and filtering: Companies use proprietary algorithms to filter and process the raw DNA data. AncestryDNA uses algorithms called Timber and Underdog to phase data and filter out high-frequency segments. Other companies may use different methods, leading to variations in reported shared cM.
  3. Total cM calculations: The total amount of cM a person has can vary between companies. 23andMe reports about 7,440 cM total and AncestryDNA seems to use around 6,800-7,000 cM total.
  4. Reporting of segments: Some companies like 23andMe and FamilyTreeDNA provide detailed segment data. AncestryDNA does not show specific segment information.
  5. Confidence levels: Companies may assign different confidence levels or relationship probabilities based on shared cM. For example, AncestryDNA previously used confidence scores like “Extremely High” for cMs greater than 60.
  6. Handling of small segments: Companies differ in how they handle very small matching segments, with some including segments as small as one cM and others excluding anything below their threshold.

These differences in methodologies can result in variations in reported shared cM and relationship estimates between companies for the same pair of individuals. This is why matches and relationship predictions may not be identical across different testing companies.

Centimorgan, Wikipedia, This page was last edited on 1 May 2024, https://en.wikipedia.org/wiki/Centimorgan

What’s the difference between shared centimorgans and shared segments?, 11 Nov 2019, The Tech Initiative, https://www.thetech.org/ask-a-geneticist/articles/2019/centimorgans-vs-shared-segments/

centiMorgan, Internatioal Society of Genetic Genealogy, This page was last edited on 15 August 2024, https://isogg.org/wiki/CentiMorgan

[40] Hansen, Annelie, Untangling the Centimorgans on Your DNA Test, FamilySearch Blog, https://www.familysearch.org/en/blog/centimorgan-chart-understanding-dna

Green Dragon Genealogy, Yes, but what EXACTLY is a centiMorgan?, 19 Sep 2021, Green Dragon Genealogy,https://greendragongenealogy.co.uk/dna/yes-but-what-exactly-is-a-centimorgan/

[41] Autosomal DNA match thresholds, International Society of Genetic Genealogy Wiki, This page was last edited on 31 August 2024, https://isogg.org/wiki/Autosomal_DNA_match_thresholds

[42] Autosomal DNA Statistics, International Society of Genetic Genealogy Wiki, This page was last edited on 17 October 2022, https://isogg.org/wiki/Autosomal_DNA_statistics

Autosomal DNA match thresholds, International Society of Genetic Genealogy Wiki, This page was last edited on 31 August 2024, https://isogg.org/wiki/Autosomal_DNA_match_thresholds

Estes, Roberta , Comparing DNA Results – Different Tests at the Same Testing Company, DNAeXplained – Genetic Genealogy Blog, 18 May 2023, https://dna-explained.com/2023/05/18/comparing-dna-results-different-tests-at-the-same-testing-company/

Autosomal DNA testing comparison chart, International Society of Genetic Genealogy Wiki, This page was last edited on 8 October 2024, https://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart

[43] Phasing, International Society of Genetic Genealogy Wiki, This page was last edited on 24 May 2024, https://isogg.org/wiki/Phasing

A Guide to Phasing from Illumina: https://youtu.be/15NPZCGP_e4

Autosomal DNA match thresholds, International Society of Genetic Genealogy Wiki, This page was last edited on 31 August 2024, https://isogg.org/wiki/Autosomal_DNA_match_thresholds

Davis DJ, Challis JH. Automatic segment filtering procedure for processing non-stationary signals. J Biomech. 2020 Mar 5;101:109619. doi: 10.1016/j.jbiomech.2020.109619. Epub 2020 Jan 9. PMID: 31952818.

Auswandererkarten or German Emigration Maps

There was a point in my long and focused research to document the immigration of our German ancestors that I came upon a map in my research. The map is 49 x 65 centimeters or about 19.3 x 25.5 inches in size.

The map was created in the early 1850s and, it contained a wealth of information about major German immigration routes to America. The map documented inland European travel routes to specific intercontinental ports of departure to the United States. The map also documented various inland routes from American ports to various cities in America. The map also provided information on the main routes for immigrants traveling in North America, measured in miles and the estimated time and cost of travel.

The map graphically portrayed the German immigrant experience in the mid 1800s in one page. It captured the gist of what I had documented through many hours of research. It was one of those moments that you look at the map and say to yourself, “Why didn’t I find this map before I started this research journey?“. While my research substantiated and explained in more detail what was depicted in the map, having the map at the beginning of the research process would have provided a great starting point.

The map is the “Auswanderer-Karte und Wegweiser nach Nordamerika” (Emigrant Map and Guide to North America), published in Stuttgart in 1852-1853 by Gotthelf Zimmermann. [1]

Map One: Zimmermann’s Emigrant Map & Guide to North America

See also a 1970 x 1478 pixel sized version of the map.

The Significance of Auswandererkarten

Auswandererkarten, or German emigration maps in the mid 1800s offered detailed information about migrating to the United States. Special maps like the 1853 “Emigrant Map and Guide to North America” were published in Germany to aid emigrants, providing detailed travel information on routes, ports, and settlements in the United States.

Emigration maps were published as separate items for guidance, advertised in German newspapers and were published as part of emigrant guides and handbooks. These maps, together with the weekly posting of departing ship schedules in German newspapers satisfied the needs of a growing market of German emigrants heading to the United States in the 1830s through 1850s.

The emigration maps provide a wealth of information, graphically depicting the predominate immigration routes in the mid 1800s. The routes are based on the transportation networks (e.g. road, canal, and rail) and major ports of departure and ports of entry that existed at the time. They capture an historical and visual snapshot of the development of the transcontinental transportation network that Germans utilized in the mid 1800s to immigrate to the United States. [2]

Here are some key details and general observations about these emigration maps :

  • They provided information for Germans planning to emigrate to the United States and other parts of North America, showing specific routes, travel times, ports of arrival, and potential settlement locations.
  • The maps were at times part of written travel guides with practical advice for emigrants on the journey, arrival ports, transportation options, costs, and life in America.
  • They were published by book publishers, map makers, emigration societies and travel agencies catering to the large numbers of Germans emigrating in the nineteenth century.
  • By depicting the routes, travel information and settlement locations, these maps provide a reflection of where Germans migrated to specific areas in North America.
  • From an historical perspective, these maps reflected the current outlines of the transportation infrastructure in Europe and the United States.
  • The maps provide a prescient graphic outline of the immigration patterns of where Germans eventually settled in the United States.

The Relationship of Emigrant Maps and Migration Patterns

These emigration maps did not cause massive upswings of Germans immigrating to the United States. Nor did they have a significant influence on the migration and settlement patterns of German immigrants in America. [3] This line of reasoning is akin to saying that since fireman are always around fires, they cause fires. To mix metaphors, it is a bit of the tail wagging the dog.

In a book, ‘A History of American in 100 Maps’, Susan Schulten chose this map as one of the hundrend influential maps of the United States. “The maps in this volume were made in vastly different contexts. Yet when considered together, they underscore the persuasive power of cartography.” [4]

Schulten points out that richly colored map was part of the large corpus of immigrant literature associated with the immigrant expansion of the United States in the mid 1800s.

“At first glance, it shows prospective emigrants a range of destinations that awaited them … . But a closer look shows not only patterns of immigration but also the more fundamental dynamics that contributed to the Civil War.”

“… (W)hile this map was designed for one purpose, it inadvertently reveals a much larger set of forces that increasingly differentiated the slave-based agricultural economy of the South from the free-market wage economy in the North. And by guiding immigrants to the latter, the map actually helps us understand the way that immigration was both a cause and consequence of that growing regional distinction, which ultimately led to the sectional crisis.” [5]

I believe the above quote correctly points to ‘a larger set of forces‘ that influenced German migration in the antebellum United States. The map also reflects the imbalance of the growth of the transportation infrastructure between the northern and southern states in the mid 1800s.

Whether the map and other emigrant maps played an influential role in guiding immigrants to the north is subject to debate. The above quote does not imply this map or German immigrants had a fundamental role in the emerging differences between the north and the south. Schulten’s observations point to the map’s reflection of the current state of affairs in the mid 1800s.

Based on various historical studies of immigrant letters and chain migration, maps and other forms of publications did not necessarily play an active, casual, or dominant role in directing immigrants to particular areas of the United States or actively guide or steer immigrants to the northeast and mid-west regions of the antebellum period. Maps of the 1850s were the reflection of the regionalized industrial growth in the United States. [6]

Whether one does immigration history by the numbers or by the letters, the results show a striking congruence. The decision to emigrate was very much a bottom-up decision. Private sources of information, above all immigrant letters, were much more influential than any public sources, be they guidebooks or state immigration agencies, in determining immigrants’ destinations. [7]

While opposition to slavery was widespread among nineteenth century German immigrants and many were active abolitionists, their attitudes were complex and varied by individual, class and circumstance. Views on the issue of slavery were not a major cause of migratory patterns. [8]

Illustration One: A Spurious Correlation: Emigration Maps and German Immigration Trends and Migratory Patterns

Click for Larger View

The views or conclusions about the influence of maps and publications on immigrant patterns are examples of what I believe to be a spurious correlation between the existence of emigration maps and migration trends and patterns. In this instance, a spurious correlation gives the false appearance of a causal relationship between two variables (e.g. maps and German emigration), when in reality the association is due to both variables being influenced by a number of other factors (e.g. push and pull migration factors, chain migration patterns, transportation infrastructure development in Europe and America, the refinement of packet ships and their schedules, etc). Identifying spurious correlations requires a careful analysis of the evidence and teasing out the effects of potential confounding variables.

Emigrant maps, in general, were specific tools to facilitate an emigrant’s journey. They did not necessarily promote or determine an emigrant’s path. However, like maps in the twentieth century, I would imagine maps in the mid 1800s in Germany may have sparked ideas of adventure or bolster decisions to make decisive moves to America in the minds of some. For the most part, they were an aid in helping immigrants that had already made their minds up in emigrating to a specific area or region of the United States.

In a society dominated by small towns and villages, horizons were narrow, local sentiments strong and information passed between generations and those you knew. The decisions made by German emigrants were not made in a vacuum. Local and regional socio-economic and political factors created a set of unique ‘push’ factors for them to consider emigrating from their homeland.

Their subsequent journey to America was also influenced by information they may have garnered from local community members who had descendants who migrated to America in the late 1700’s and early 1800’s. Travel agents and brokers, and German publications, such as maps, also provided to some degree information that may have facilitated their decisions to emigrate and guided their specific paths to their destinations..

As stated in prior stories, the areas in Germany where our relatives migrated from had a long tradition of migrating to America. Their specific route getting to America was different from the Baden emigrants in the 1700s and early 1800s. However, there may have been a strong likelihood that they followed the guidance from past generations from their local communities to settle in places that prior generations had settled or use those places as starting points to go further. Even without specific contacts, they may had at least a general idea of settling in the ‘Palatine area’ along the Mohawk River in New York state where past generations originally settled.

Regardless of the relative influence that emigrant maps may have had on emigration patterns, Zimmerman’s emigrant map provides an amazing, graphic snapshot of possible German migratory patterns in the mid 1800s. It is a great 1850s version of the contemporary travel map of the twentieth century.

(O)ld maps are valuable as both records and agents of history. Across five centuries, artifacts such as these have guided exploration, conquest, and settlement but also politics, commerce, science, medicine, education, bureaucracy, reform, and entertainment. Whether made for military strategy or moral reform, to encourage settlement or investigate disease, maps both reflect and mediate change. They tell us what people knew, what they thought they knew, what they hoped for, and what they feared. They invest information with meaning by translating it into visual form, thereby reflecting decisions about how the world ought to be seen. They capture the irreducible complexity and contingency of the past. Above all, they remind us that the past is not just a chronological story, but a spatial one as well.” [9]

Advertisements for the Auswanderer-Karte und Wegweiser nach Nordamerika

The “Auswanderer-Karte und Wegweiser nach Nordamerika” (Emigrant Map and Guide to North America) was published in Stuttgart, which was located in the Kingdom of Württemberg, around 1852. This is around the time that ancestors of the Griffis family emigrated from Baden. This is the year that John Speber departed from Le Havre to New York. It is five years after Catherine Fliegel departed from Le Havre for the port of New York city. It is three years before the remainder of the Fliegel family embarked from Le Havre to New York City.

The map was published by J.B. Metzler. The J.B. Metzler publishing house was one of he oldest publishing houses in Gemany. It was founded in Stuttgart in 1682 by August Metzler. [10] Metzler advertised the emigration map in German papers and offered special rates for bulk orders by emigration agents. [11]

While the map is often referenced as the ‘1853 German Map’, its existence is documented prior to 1853. For example, the pamphlet or map is referenced in an advertisement in the newspaper Leipziger Freitag in September 1852 [12]

Advertisement for Zimmermann’s Map in the Leipziger Zeitung, September 1852

The advertisement states:

“Mesler in Stuttgart has just published: Gotthel Zimmermann’s emigrant map and guide to North America”

Emigrant Map and Directions to North America, containing the European ports of departure, the routes that the ships follow at sea, the disembarkation points in North America, the land and water routes from the disembarkation points to the interior of America, the distances of the main American towns and cities (Hauptorte) from one another in German hours, and the cost of the trip on the main routes in guilder and thaler. Presented in an easy to understand form for everyone, especially emigrating artisans and farmers.

Cartonized 7 1/2 Silver Groschen

“This large map, printed in 3 colors, is distinguished above all by its cheap price, clarity and basics, so that it is easier to read in Latin script for the less inclined, all frames are given in German print.”

Another example of an advertisement for the map was found in the newspaper, Kempter Zeitung, in March 1854. [13]

Advertisement for Zimmermann’s Map in the Kempter Zeitung, Mar 12 1854

The following is a translation of the advertisement.

“Zimmerman, Emigrant Map and Guide to North America in which the European ports of departure, the landing places in North America, the land and waterways from these landing places to the interior of America, the distances of the main places in America from each other according to German hours, the of the main routes in Rhenish guilders and in prussian thaler are presented in an easily understandable way. Fourth edition. In case. Price 24 fr.”

The map was listed in a German book bibliography, Allgemeines Deutsches Bücher-Lexikon, as late as 1858. The Allgemeines Deutsches Bücher-Lexikon was a comprehensive German book lexicon or bibliography published in the 19th century. [14] The map was advertised in German newspapers and sold in multiple editions through the late 1850s, indicating demand for such emigration maps.

The Audience and Marketing of the Map

The map was intended for a specific audience: Germans who had an interest or plans for immigrating to America. The introduction of the Map, found in the lower right corner of the map states:

“Emigrant Map and Directions to North America, containing the European ports of departure, the routes that the ships follow at sea, the disembarkation points in North America, the land and water routes from the disembarkation points to the interior of America, the distances of the main American towns and cities [main places] from one another in German hours, and the cost of the trip on the main routes in guilder and thaler. Presented in an easy to understand form for everyone, especially emigrating artisans and farmers.”

“Gotthelf Zimmermann. Second Edition”

“North (Nord) America” in Fraktur Calligraphy

With the exception of the title of the map (which appears to use Textra print [15] ), the map is using Fraktur typeface which was a common typeface of the day. Fraktur type was used for printing in Germany throughout the nineteenth century. Frakur typeface became the most common German blackletter typeface from the mid-16th century until the early 20th century. [16] As the description of the map states: the map ispresented in an easy to understand form for everyone, especially emigrating artisans and farmers“.

The map was intended to be published to fit on one piece of paper. The goal obviously was to fit both northern Europe and the United States and related information on the face of one piece of paper. The ability to fit this geographical space onto one page necessitated the need to take liberties on the accuracy of scale. This is explicitly mentioned in a note that was placed in the middle of the Atlantic ocean near Spain. The European countries and the American states are also not to scale on the map.

Annotation In-Between the Two Continents on the Map [17]

“The distance between Europe and America is relatively far greater than could be shown in the drawing. To save space, the two parts of the world had to be brought together here.”

Information on Travel Distance and Cost

In the upper left hand corner of the map, traditional Fraktur German typography identifies cities and towns, and the distance and travel cost from each of the ports along the Atlantic coast to the interior towns and cities. Cost is provided in guilders, kreuzers and silver groschen. [18]

Illustration Two: Travel Time and Cost of Travel in the Zimmermann Map

Click for Larger View

An Example of a Baden Kreuzer

Six Kreuzers – Lepold I, Issued by the Grand Duchy of Baden (1830-1852) Source: 6 Kreuzers – Leopold I, Numista, https://en.numista.com/catalogue/pieces36798.html

Comparative Time Table of Time 1868 [19]

Click for Larger View

(F)or example, when it was noon in New York, it was 11:10 in Indianapolis, 11:19 in Cincinnati, 11:24 in Columbus, 11:30 in Cleveland, 11:36 in Pittsburgh, 11:56 in Philadelphia, and 12:12 in Boston—that is to say, local time was defined relative to the sun at midday.”[20]

It is not known what “nach deutschen Stunden“, by German hours, means in the context of Zimmermann’s calculation of the amount of time to travel between designated cities. It is not known if ‘German time’ implies the use of a standardized base for computing time for the figures found in the map. This could be possible since time was not standardized in the United States.

The growth of railroads in the 1800s exposed the problems with every locality having its own solar time, and drove the adoption of standardized time zones that enabled more efficient train scheduling and safer operations. But this transition occurred gradually over many decades. In the early-to-mid 1800s, each town kept its own local time, usually based on “solar time” where noon was when the sun was highest in the sky. This meant adjacent towns could have slightly different local times. Railroads initially had to deal with this patchwork of local times when scheduling trains. [21]

The map lists twenty-one combinations of trips and their distances from major United States cities. For example Part I lists routes from New York to various inland destinations.

Click for Larger View

The following is a rough translation of the estimated time in hours it took to travel between New York City and the various destination points.

Click for Larger View

It is not clear what mode of transportation was used to calculate the estimated number of hours to travel to each of these various places. I am assuming many of the above travel routes between New York and the various places listed were based on travel by water.

Comparing the estimated time for travel in the Zimmermann map with American travel guides published around the same time period suggests the ‘Zimmermann travel’ was based on travel on canals, rivers, or lakes.

This is obviously the case traveling to “Albany on the Hudson River” (nach Albany auf hudsonfluss). For example, the Zimmerman map indicates the trip between New York city and Albany was estimated to be 65 hours in 1853 (perhaps based on data earlier than 1853 since that was the publication date). An 1851 travel publication indicated a train ride from New York to Albany took 10 hours (see below)

Travel on the Housatonic Railroad between New York City and Albany 1848 [22]

Hudson river days boats were also available in 1851 (see below). [23] Whether German immigrants utilized these boats or other slower vessels to travel further inland in New York state is not certain.

Hudson River Day Boats to Albany

Click for Larger View

Major Land Routes in Europe Portrayed in the Map

The ‘1853’ map was the second edition of Zimmermann’s map. As such it purportedly represents knowledge of the transportation networks in Europe and the United States around that time.

There is no explicit legend defining what the red lines denote or mean in the map. It is not known if the red routes on the map are intended solely to denote railways or routes that include roadways and railways. Canals and rivers are in blue or grey (depending on what version of the map you are viewing).

Map Two: Highlighted Possible Immigration Routes for John Sperber in 1852 on the ‘1853’ Zimmemann Map

Based on an historical analysis of German migration, we know that the red routes in the map signify popular routes that German emigrants had taken to major European ports of departure for America between 1830 to the 1860s and perhaps onward. However, based on the historical development of French and German railway networks around 1850-1852, I believe the red routes on the map signify routes that include a combination of road and railway travel not just rail travel. (See map two)

As indicated in a prior stories, a great great grandfather of mine, John Sperber, immigrated to America from Baden-Baden, Grand Duchy of Baden which is close to and on the other side of the Rhine River to Strasbourg, France. Based on historical evidence, I believe he traveled from Baden-Baden to Le Havre France and departed in 1852 to New York City. At the time of his journey the railway lines between Paris and Strasbourg were not complete. (See map three below)

If John traveled by railway, his options were limited. The rail line between Paris and Strasbourg was built and operated by the Compagnie du chemin de fer de Paris à Strasbourg, which later became part of the Chemins de fer de l’Est This railway line between Paris and Strasbourg was complete after John arrived to the United States in 1852. It was not available for him when he emigrated to the United States.

The first section of the French railway line between Le Havre and Strasbourg was opened in 1849. This first section connected Paris to Châlons-sur-Marne (see map three below). In 1850 a line from Nancy to Frouard and a line from Châlons to Vitry-le-François were completed. In the following year, a line from Vitry-le-François to Commercy as well as a line from Sarrebourg to Strasbourg were completed. Finally, in 1852, the year John Sperber emigrated, the sections between Commercy and Frouard, and the line between Nancy and Sarrebourg were opened. The 1852 sections were probably open after John’s voyage in June 1852.  [24]

During this period, railway technology and infrastructure were rapidly developing. The rapid development had its impact on the production of maps. It has been observed that for American maps “even the most accurately drawn map which spent a month or two in production might miss more new railroad mileage during these years than had existed in the entire country in the 1830s or early 1840s. Some mapmakers tried to anticipate this fluidity by building their expectations for expansion into their maps, only to see those plans unrealized as funding fell through or construction was temporarily halted.” [25] I imagine this was an issue faced by the German and French map makers as well.

As reflected in map three, I have modified and removed from the original source map all of the rail lines that were built between 1850 and 1856. You can see of illustrative purposes, however, remnants of removed lines for the railways completed in this six year period. John Sperber may not have been able to travel by rail between Strasbourg, Nancy and Vitry-le-François. Even if they were able to travel by train, his journey would have been interrupted and punctuated with the need to travel by roadways where the train line was under construction. [26]

Map Three: French Railway System 1842 – 1850

Many of the major contemporary road arteries in France follow the routes of royal postal roads that were originally built in the 1700s. The French postal roads of the 1700s were innovative in their design and construction. Many of the these postal routes survived and became the major roadways in France. In fact, all of the roadways in the along the route from Strasbourg to Le Havre in 1853 are part of the old postal route system.

Map four below depicts the postal roads in northern France that linked major towns and cities in France in 1833. The creation of the map is the result of analyzing the changes over time of the expansion of postal routes in France through time. I have highlighted the postal roads that followed the possible route that John Sperber had taken to reach the post of Le Havre.

Based on the above analysis, I believe the Zimmermann ‘red route’ between Strasbourg and Le Havre merely denotes a popular route to Le havre that included roadway and railway, depending on when one traveled across northern France.

Map Four: French Postal Roads and Main Cities and Towns in 1833 and the Highlighted Possible Route of John Sperber from Strasbourg to Le Havre [27]

Click for Larger View

Between 1850 and 1853, the Baden to Bremen route probably was an effective alternative route for John Sperber’s consideration or others from the Grand Duchy of Baden. Bremen could have been reached by roadways from Baden. Bremen could also be reached through the use of a combination of train (Baden Main Line), waterway (the Rhine River to Cologne) and then rail via Hanover and Bremen. (See map five)

Map Five: Major Interior Rivers Served By Steam Transportation & Rail Lines to Docks of Bremen and Hamburg, 1847 [28]

Click for Larger View

Map six below is a portion of Zimmermann’s map that shows the same route that is reflected in map five.

Map Six: Portion of Zimmerman Map Showing Route from Baden-Baden to Bremen and Hamburg

Based on historical evidence on the development of German railways in the 1840s and 1850s, it is reasonable to assume that the red travel paths in the Zimmermann map for this particular “Baden to Bremen” route denote rail lines connected with waterways .

Depending on the specific popular routes in the Zimmermann map, the red lines may denote railways or roadways. Nonetheless, the emigrant map serves its purpose of providing a simplified depiction of the major routes to outgoing European ports.

Major Inland Routes in America Portrayed in the Map

The first thing that comes to mind when viewing the American cities and towns in Zimmermann’s map is why some of these locations were chosen and not others. Many of the cities in the map were obvious choices given German immigration patterns since the early 1800s.

“The sheer volume of detailed information in the map … raises the question of how the mapmaker assembled it. What advertising and promotional materials could he draw on? Newspapers? Firsthand reports from sales agents or people who had already emigrated? Related guidebooks or maps? Train and ship schedules? In any case, the information conveyed by this map was part of a broader ecosystem of knowledge of varying reliability bound up with the experiences and agency of those who had made or would make the journey.” [29]

Zimmermann may have obtained information for his map from various sources. He may have utilized the information contained in other German emigration maps, newspapers, and popular German travel and immigration books as a reflection of accumulated knowledge of migration. Information on travel schedules and major shipping routes were readily available in German newsprint.

Zimmermann may have also relied on pocket travel guides that were published in America. Many guides contained multiple large scale maps. These travel guides and maps often provided detailed depictions of travel routes, such as bridges and tunnels that are not easily seen on other, larger maps.

“Probably the best (American) nineteenth century railroad maps were those which appeared in “pocket” travel guides. Appearing first in the 1840s, some were published monthly; others, semi-annually or annually, often under slightly changed names. … Each went through many editions.” [30]

The Zimmermann map highlighted the major American port cities of the mid 1800s like New York, Philadelphia, Boston, Baltimore and New Orleans. New York was major port of entry during the time period.

“Her connection with the interior was a prime cause of New York’s commercial supremacy, and the two together account for the growing favor shown her by immigrants. In the middle of the century Buffalo, Cleveland, and Milwaukee were the distributing points for those bound to the Northwest, and to reach these cities the Erie Canal and, after 1846, the railroad from New York to Buffalo were by far the quickest and the cheapest routes. For those bound to the Middle West, Wheeling, Pittsburgh, Cincinnati, and St. Louis were the distributing points; and for reaching them New York offerred facilities as good as those from Philadelphia and better than those from Boston or Baltimore. New Orleans was favorably situated for such as were bound for the Mississippi Valley and she did receive a considerable number of immigrants; but the voyage was two or three weeks longer than to New York, the ships sailing thither from Europe were inferior, the journey up the Mississippi to St. Louis was unpleasant, dangerous, and little shorter than from New York, and above all, the dread of yellow fever and other maladies common among strangers in a southern climate combined to deter most Europeans from choosing that route.” [31]

The Zimmermann map also identifies inland cities in the midwest that were popular destinations for German immigrants. In the nineteenth century, German immigrants settled in Midwest, where land was available. Cities along the Great Lakes, the Ohio River, and the Mississippi and Missouri Rivers attracted a large German element. The Midwestern cities of Cleveland, Cincinnati, Fort Wayne, Milwaukee, Cincinnati, St. Louis, Chicago were favored destinations of German immigrants. The Northern Kentucky and Louisville area along the Ohio River were also a popular destinations.  Dubuque and Davenport, Iowa and Omaha, Nebraska, were also areas where Germans settled.  By 1850 there were 5,000 Germans in Ann Arbor, Michigan. [32]

The presence of smaller cities and towns on the Zimmermann map are a bit puzzling, perhaps due to my lack of knowledge of the history of the towns. Smaller inland towns like Guilford and Hanover in New Hampshire; Montpellier in Vermont; and the Maine towns of Portland, Waterville, Augusta and Paris are identified along red routes on the map. Perhaps these towns were noted on the map based on reports from earlier German migrants, earlier settlements or efforts by land developers to attract settlers. [33]

It is interesting to compare Zimmermann’s simplified, elegant emigrant map with a more detailed American map that shows canals, railroads, telegraph lines and principal stage routes. [34] If compare the transportation networks that existed in 1850 (see map seven) with the simplified ‘1853’ Zimmermann emigrant map (see map eight), one can see the transportation links with the above mentioned towns and cities in Vermont, New Hampshire and Maine. All of these towns had rail connections.

Map Seven: Vermont, New Hampshire, and Maine 1850 [35]

Map seven depicts railways, roadways, and waterways. As evident in the 1850 map, the towns highlighted in Zimmermann’s map are linked to other towns through railways, waterways and roadways.

Map Eight: Portion of Zimmermann’s Emigrant Map: Vermont, New Hampshire, and Maine

Screenshot

Similar to my conclusion regarding what the red lines denote for travel paths on the European continent, I believe the red lines depicting travel routes to inland cities in the United States also represent ‘popular routes’ that are a combination of roadways, railways and waterways.

Comparing Transportation Networks in the 1953 Zimmermann Map and German Population Density in 1870

While this map was designed for the purpose of providing guidance to German immigrants for planning travel to the United States, it provided a ‘snapshot’ of the current state of affairs for German émigrés that traveled to America.

Railroads and waterways, natural and man made, had a significant influence on German immigration and settlement patterns in the United States during the 19th century. In the 1700s and early 1800s, a majority of German immigrants settled in cities and rural areas near the major ports on the eastern seacoast roadways and waterways increased their travel inward on the American continent. [36]

In the central part of America, many German immigrants initially settled in cities along major waterways like the Missouri and Mississippi Rivers, as these provided transportation routes into the frontier. Towns with large German populations developed along the Missouri River in the early to mid-1800s. [37]

The opening of the Ohio & Erie Canal in the 1830s attracted more German immigrants to settle in Cleveland and other cities in Ohio. Canals in general improved transportation and opened up new areas for settlement before railroads became dominant. [38]

Railroad construction in the mid to late 1800s enabled German immigrants to travel further inland to establish new settlements, especially in the Midwest. Many Germans worked as laborers to build the railroads. As railroads expanded, new waves of German immigrants arrived and often settled in areas that already had established German communities. However, the core areas of German settlement did not significantly expand, with the exception of a few new settlements along railroad lines in the 1870s-1880s. [39]

Railroads played a key role in the rapid growth of cities like Chicago, St. Louis and Milwaukee which developed large German populations in the late nineteenth century. There was a “German triangle” in the Midwest connected by rail between New York, Minneapolis, St. Louis and Baltimore where there was a concentration of German settlement.

While this pamphlet-sized map was designed for the purpose of providing guidance for planning travel to the United States, it provided a prescient future view of settlement patterns for subsequent generations of German-Americans. The significant influence on the history of American transportation networks on nineteenth century German immigration and settlement patterns is apparent if we compare Zimmermann’s map with density settlement patterns of Germans in 1870.


Title Page of 1870 CensusThe Statistics of the United States

Click for Larger View

“The 1870 census provided the nation with an astounding array of graphic and cartographic depictions of its state of geographic knowledge.” [40] A national atlas produced by the U.S. government was first realized in the Statistical Atlas issued by the Bureau of the Census with the 1870 census. The U.S. census had been transformed from a massive tabulating project to assist in apportioning Congressional representation among the states to a quantitative scientific accounting of numerous aspects of the nation’s many human geographies.

“Members of the fledgling American Geographical Society and American Statistical Society, including the geographer Daniel C. Gilman of Yale University, Samuel B. Ruggles of the American Geographical Society, and Edward Jarvis of the American Statistical Association, had attended meetings of the International Statistical Institute in Europe where new ideas concerning the graphic presentation of information were regularly discussed.” [41]

The 1870 census and its supplemental publications introduced more sophisticated capabilities for visualizing quantitative information, both graphically in charts and cartographically in thematic maps. The Census Office issued its first 1870 census thematic maps in its final reports, just before publishing the Statistical Atlas. These reports included a total of some twenty-six thematic maps.  [42] The atlas appeared as a complete volume in 1874.


Map nine is from the Ninth U.S. Census. It indicates the density of people of German descent living in the eastern half of the United States in 1870, twenty years after the publication of Zimmermann’s map. The 1870 U.S. Census map provides the population density patterns of people of German descent in the eastern portion of the United States. The U.S. Census map indicates that individuals of German descent are largely found along and above the Missouri and Ohio Rivers in the mid-west. The Mason-Dixon line appears to be an imaginary line for Germans settling in the United States. Individual of German descent are found in New York, Pennsylvania, parts of Massachusetts and Connecticut, the Great Lakes region above the Ohio River and along the Missouri River.

Map Nine: Density of German Population in U.S. in 1870

Click for Larger View | Source: A. de Witzleben, German Population 9th Census, Page 325, in Francis A Walker, Superintendent of Census, Ninth census – Volume I,  The Statistics of the Population of the United States, Washington, Government Printing Office, 1872,  Page 325, https://www.google.com/books/edition/Ninth_Census_volumes/0ngZm56S-7sC?hl=en&gbpv=1

It is interesting to compare the density patterns of the German population in 1870 with the transportation routes depicted in Zimmermann’s map. I abstracted the transportation routes of the Northeastern United States from the Zimmermann map and I tried to overlay both maps. The latitudinal and longitudinal scales of each map are different. I was unsuccessful in modifying the dimensions of each map to make them conform and consequently was unable to overlay both maps to provide a visual comparison. The image below graphically shows what I was attempting.

Illustration Three: Attempted Overlay of Zimmermann’s Map with 1870 U.S. Census Density Map of German Population

Click for Larger View

Despite my failure to meld and overlay both maps, if both maps are closely examined (maps ten and eleven), you can see that Germans ultimately settled along major transportation networks that existed in the 1850’s. Zimmermann’s map depicted the major transportation arteries to cities in the United States at this time. I have taken the northeastern portions of each map for comparison. In map eleven, I have highlighted in yellow the major routes in Zimmermann’s map that correspond with dense areas of German population in 1870.

Map Ten: Density of German Population in 1870 in North East and North Central United States

Click for Larger View

Map Eleven: Transportation Netweks Abstracted from Zimmermann’s Emigrant Map

The rapid development of rail lines and the pre-existing river transportation networks enabled and encouraged German immigrants to spread westward from initial entry points on the East Coast, concentrating in the Midwest and the Plains states that became the “German belt” in the 19th century. [43] The transportation infrastructure had a fundamental effect on the settlement patterns and density of German immigrant communities. [44]

German immigrants often traveled inland to the Midwest after arriving at ports like New York, Philadelphia, Baltimore, and New Orleans. They also to a lessor extent used the Mississippi, Ohio, and Missouri river systems to reach areas in the “German triangle” between Cincinnati, Milwaukee, and St. Louis where many of them settled. [45]

The expansion of railroads in the mid-1800s enabled German immigrants to more easily travel west from the East Coast to settle in the Midwest and establish farms. States in the “German belt” stretching from Pennsylvania to Oregon saw high concentrations of German settlement.

Cities along major waterways like the Great Lakes, Ohio River, and Mississippi River, such as Milwaukee, Cincinnati, St. Louis, and Chicago, became centers of large German-American populations in the 1800s. Access to both rail and water transportation supported rapid growth and industrialization in these areas.

A Map to Guide and a Map to Predict

Zimmermann’s map was a simple map that contained a wide range of information for German emigrants making their journey to America. While it served a very useful purpose in the 1850s, his map reflected the current outlines of the transportation infrastructure in Europe and the United States. It also provided a glimpse of the emerging graphic outline of the immigration patterns of where Germans and their families eventually settled in the United States.

Maps “record efforts to make sense of the world in physical terms. They capture what people knew, what they thought they knew, what they hoped for, and what they feared. They invest information with meaning by translating it into visual form, and in so doing reveal decisions about how the world ought to be seen. Above all, they demonstrate that the past was not just a chronological story but a spatial one as well. ” [46]

Sources

Feature banner: The banner is an amalgam of parts of the 1852-1853 immigration map that is discussed in the story.

Source: Gotthelf Zimmermann, Auswanderer-Karte und Wegweiser nach Nordamerika, 2nd ed. (Stuttgart: J.B. Metzler’schen Buchh., 1853), Library of Congress Geography and Map Division, Washington, DC, http://www.loc.gov/resource/g3701e.ct000244

[1] Zimmermann, Gotthelf. Auswanderer-Karte und Wegweiser nach Nordamerika. Stuttgart: J.B. Metzler’schen Buchh, 1853. Map. https://www.loc.gov/item/98687132/

[2] Ronald Grim discusses Grim, Ronald, Mapping Migration andSettlement, The Newberry, https://mappingmovement.newberry.org/mapping-migration/

For an interesting perspective on cartography andAmerican history, see: Mapping Movement, The Newberry, https://mappingmovement.newberry.org

[3] For example, a February 2024 Reddit discussion thread, titled “A German map of American ports and major cities, intended for use by travelers and immigrants to the United States, circa 1853. The German immigration wave to the US soared to then-record numbers around this time”, implies that the map had a substantial correlation with German migration to the United States. https://www.reddit.com/r/TheWayWeWere/comments/1ajwfvd/a_german_map_of_american_ports_and_major_cities/

Danzer, Gerald A. Danzer with James Akerman, American Railroad Maps, 1828 – 1876, The Newberry, https://mappingmovement.newberry.org/american-railroad-maps-1828-1876/

[4] Susan Schulten, A History of America in 100 Maps, Chicago: The University of Chicago Press, 2018, Page 9

[5] Schulten, Susan, How Maps Reveal, and Conceal, History, Progress: A Blog for American History, https://www.oah.org/process-blog/schulten-maps/

See also:

Susan Schulten, A History of America in 100 Maps, Chicago: The University of Chicago Press, 2018, Pages 138 – 239

[6] Kamphoefner, Walter D. “Immigrant Epistolary and Epistemology: On the Motivators and Mentality of Nineteenth-Century German Immigrants.” Journal of American Ethnic History, vol. 28, no. 3, 2009, pp. 34–54. JSTORhttp://www.jstor.org/stable/40543427

For a general review of research on German emigration and immigration, see Helbich, Wolfgang. “German Research on German Migration to the United States.” Amerikastudien / American Studies, vol. 54, no. 3, 2009, pp. 383–404. JSTOR, http://www.jstor.org/stable/41158447

See also:

Félix Krawatzek and Gwendolyn Sasse, Integration and Identities: The Effects of Time, Migrant Networks, and Political Crises on Germans in the United States. Comparative Studies in Society and History, 60(4), June 2018, 1029-1065. doi:10.1017/S0010417518000373 https://www.cambridge.org/core/journals/comparative-studies-in-society-and-history/article/abs/integration-and-identities-the-effects-of-time-migrant-networks-and-political-crises-on-germans-in-the-united-states/A5B951CA7AEB2C2C33958799C40FDDA2

See also other work of Krawatzek and Sasse where they developed a computer-aided textual analysis of about 6,000 letters sent between the US and Germany between 1830 and 1970. Their contents allowed the researchers to trace how migrants’ identities and transnational ties changed over the decades.  

Félix Krawatzek and Gwendolyn Sasse, Writing home: how German immigrants found their place in the US, February 18, 20016, The Conversation, https://theconversation.com/writing-home-how-german-immigrants-found-their-place-in-the-us-53342

Félix Krawatzek, Gwendolyn Sasse, The simultaneity of feeling German and being American: Analyzing 150 years of private migrant correspondence, Migration Studies, Volume 8, Issue 2, June 2020, Pages 161–188  https://doi.org/10.1093/migration/mny014

Félix Krawatzek and Gwendolyn Sasse, Deciphering Migrants’ Letters, November 28, 2018, comparative Studies in Society and History, https://sites.lsa.umich.edu/cssh/tag/krawatzek/

Walter D. Kamphoefner, Wolfgang Helbich, et al., Editors., News from the Land of Freedom: German Immigrants Write Home (Documents in American Social History) : Cornell University Press, 1991.

Karl Dargel, Tyler Hoerr, Petar Milijic,  Economic Migration: Tracing Chain Migration through Migrant Letters in an Economic Framework, Global Histories, Special Issue (Feb 2019) Pages 19 -30

Moltmann, Günter. “Migrations from Germany to North America: New Perspectives.” Reviews in American History, vol. 14, no. 4, 1986, pp. 580–96. JSTORhttps://doi.org/10.2307/2702202 Accessed 26 Sept. 2023.

Helbich, Wolfgang. “German Research on German Migration to the United States.” Amerikastudien / American Studies, vol. 54, no. 3, 2009, pp. 383–404. JSTORhttp://www.jstor.org/stable/41158447Accessed 26 Sept. 2023.

[7] Kamphoefner, Walter D. “Immigrant Epistolary and Epistemology: On the Motivators and Mentality of Nineteenth-Century German Immigrants.” Journal of American Ethnic History, vol. 28, no. 3, 2009, pp. 48. JSTORhttp://www.jstor.org/stable/40543427

[8] Barkin, Kenneth. “Ordinary Germans, Slavery, and the U.S. Civil War.” The Journal of African American History, vol. 93, no. 1, 2008, pp. 70–79. JSTOR, http://www.jstor.org/stable/20064257

Raphael-Hernandez, H., & Wiegmink, P. (2017). German entanglements in transatlantic slavery: An introduction. Atlantic Studies14(4), 419–435. https://doi.org/10.1080/14788810.2017.1366009

Anderson, Kristen Layne, Abolitionizing Missouri: German Immigrants and Racial Ideology in Nineteenth-Century America (Antislavery, Abolition, and the Atlantic World),Baton Rouge: Louisiana State Press, 2016

Efford, Alison Clark, “German Immigrants and the Arc of Reconstruction Citizenship in the United States, 1865-1877” (2010). Hist or y F aculty Research and Publications. 285.
https://epublications.marquette.edu/hist_fac/285

Biesele, Rudolph, German Attitude Toward the Civil War, Sep 1, 1995, Texas State Historical Association, https://www.tshaonline.org/handbook/entries/german-attitude-toward-the-civil-war

[9] Schulten, Susan, How Maps Reveal, and Conceal, History, Progress: A Blog for American History, https://www.oah.org/process-blog/schulten-maps/

[10] J.B. Metzler, Wikipedia, Diese Seite wurde zuletzt am 18. März 2024, https://de.wikipedia.org/wiki/J.B._Metzler

“Der J.B. Metzler Verlag ist ein traditionsreicher geisteswissenschaftlicher Verlag. Gegründet 1682, ist er einer der ältesten Verlage Deutschlands überhaupt. Verlagsort ist Stuttgart.”

The J.B. Metzler Verlag is a traditional humanities publisher. Founded in 1682, it is one of the oldest publishing houses in Germany. Publishing place is Stuttgart.

J.B. Metzle Publishing Website , https://www.metzlerverlag.de/der-verlag/verlagsprofil

[11] This is pointed out by Mark R. Stoneman in “An 1853 Map for German-Speaking Emigrants,” Migrant Knowledge, January 30, 2022, https://migrantknowledge.org/2022/01/30/an-1853-map-for-german-speaking-emigrants/

[12] Leipziger Zeitung, No. 218, Friday, September 10, 1852  Page 4329. https://www.google.com/books/edition/_/iPxjAAAAcAAJ?hl=en&gbpv=1&pg=PA4329&dq=%22Auswanderer-Karte+und+Wegweiser+nach+Nordamerika%22

[13] Kempter Zeitung, Mar 12 1854, No. 62   Page 254 , https://www.google.com/books/edition/Kemptner_Zeitung/ScVDAAAAcAAJ?hl=en&gbpv=1&dq=kemptner%20zeitung%201854&pg=PA254&printsec=frontcover

[14] This is pointed out by Mark R. Stoneman in “An 1853 Map for German-Speaking Emigrants,” Migrant Knowledge, January 30, 2022, https://migrantknowledge.org/2022/01/30/an-1853-map-for-german-speaking-emigrants/

Heinsius, W. (1858). Allgemeines Bücher-Lexikon oder vollständiges alphabetisches Verzeichnis aller … erschienenen Bücher, welche in Deutschland und in den durch Sprache und Literatur damit verwandten Ländern gedruckt worden sind. Germany: Brockhaus. Volume 12 https://www.google.com/books/edition/Allgemeines_Bücher_Lexikon_oder_vollst/4G6LLUh1isUC?hl=en&gbpv=1&dq=%22Auswanderer-Karte+und+Wegweiser+nach+Nordamerika%22&pg=PA519&printsec=frontcover#v=onepage&q=%22Auswanderer-Karte%20und%20Wegweiser%20nach%20Nordamerika%22&f=false

[15] Textualis, also known as textura or Gothic bookhand, was the most formal and calligraphic form of blackletter script, widely used for book production in Western Europe from the 12th to 15th centuries. Textualis was most widely used in France, the Low Countries, England, and Germany.

Blackletter, Wikipedia, This page was last edited on 30 April 2024, https://en.wikipedia.org/wiki/Blackletter

[16] Fraktur, Wikipedia, This page was last edited on 8 May 2024, https://en.wikipedia.org/wiki/Fraktur

Draper, Kelly, Fraktur Basics, Aug 17, Backlog Achivists and Historians, https://www.backlog-archivists.com/blog/fraktur

The History of Old German Cursive Alphabet and typefaces, German Girl in America Blog, https://germangirlinamerica.com/old-german-cursive-alphabet-and-typefaces/

German Fraktur Alphabet

This image has an empty alt attribute; its file name is fraktur-alhabet-718x1024.jpg
Click for Larger View | Source: Old German Fraktur Letter Key, Resource: Dowloads, Project Ancestry,  https://www.projectancestry.com/downloads

Fraktur, Wikipedia, This page was last edited on 8 May 2024, https://en.wikipedia.org/wiki/Fraktur

[17] “Die Entfernung zwischen Europa und Amerika ist im Berhältnisz weit gröszer, als durch die Zeichnung dargestellt werden konnte. Wegen Raumersparnisz muszten hier die beiden Welttheille zusammegerückt werden.”

[18] “Rheinisch” means “Rhenish” and refers to the Rhineland area. So “Kreuzer rheinisch” specifies Kreuzer coins minted and used in the Rhineland currency system. In the Rhineland region of Germany, 1 Gulden was typically equal to 60 Kreuzer. In the 18th century, common larger denominations included the Reichsthaler (worth 90 Kreuzer rheinisch), the Gulden (60 Kreuzer rheinisch), and the Batzen (4 Kreuzer rheinisch).

The following provides a brief discussion of the currencies mentioned in the map.

“From 1837: the Prussia-led Zollverein customs union led to a more vigorous transition into the Prussian currency standard, with North German thalers being replaced by lower-valued Prussian thalers worth 14 to a Cologne Mark of fine silver (or 16.704 g), and with each thaler now divided into 30 silbergroschen. The Prussian thaler was also fixed at 134 South German gulden.”

Thaler, Wikipedia, This page was last edited on 9 February 2024, https://en.wikipedia.org/wiki/Thaler

The Rhenish kreuzer was a common small silver coin used for centuries in the Rhineland and nearby regions of Germany, with its value defined relative to larger units like the albus, groschen, and gulden. The kreuzer’s role was as a convenient everyday coin for smaller transactions.

The Taler – the Trade Currency of the 16th Century, Money Museum, https://moneymuseum.com/pdf/yesterday/05_Modern_Times/01%2804%29%20The%20Taler%20the%20Trade%20Currency%20of%20the%2016th%20Century.pdf

Albus (coin), Wikipedia, This page was last edited on 10 November 2023  , https://en.wikipedia.org/wiki/Albus_%28coin%29

South German gulden, Wikipedia, This page was last edited on 12 August 2023, https://en.wikipedia.org/wiki/South_German_gulden

Medieval Currencies, Money Museum, https://www.moneymuseum.com/pdf/yesterday/04_Middle_Ages/19%20Medieval%20Currencies.pdf

“In the German-speaking world, the groschen was usually worth 12 pfennigs … The later  Kreuzer, a coin worth 4 pfennigs arose from the linguistic abbreviation of the small Kreuzgroschen.”

Groschen, Wikipedia, This page was last edited on 6 April 2024, https://en.wikipedia.org/wiki/Groschen

[19] Comparative-Time Table, Showing the Time at the Principal Cities of the United States, compared with Noon at Washington, D. C., 1868, Central Pacific Railroad Photographic History Museum, http://cprr.org/Museum/Ephemera/Comparative_TT_1868.html

[20] Atack, Jeremy & Bateman, Fred & Margo, Robert. The Transportation Revolution Revisited: Towards a New Mapping of America’s Transportation Network in the 19th Century. Uploaded 12 Jan 2015, preliminary paper, ResearchGate,  Footnote 27, https://www.researchgate.net/figure/The-Railroad-Network-in-1850-1860-1870-and-1880-Mapped-Against-1860_fig3_267239718

[21] The major railroads took it upon themselves to solve the problems caused by the jumble of local times. By collectively adopting a standard time zone system in 1883, they paved the way for the nationwide standardization of time.

Time Zone, Wikipedia, This page was last edited on 16 May 2024, https://en.wikipedia.org/wiki/Time_zone

Railway Time, Wikipedia, This page was last edited on 4 January 2024, https://en.wikipedia.org/wiki/Railway_time

History of Time in the United States, This page was last edited on 6 April 2024, https://en.wikipedia.org/wiki/History_of_time_in_the_United_States

Barass, Karen, Time Zone Origins, Infoplease, Aug 24, 2020, https://www.infoplease.com/calendars/history/time-zone-origins

Standardizing time: Railways and electric telegraph, 4 Oct 2018, sciencemuseum.org,

When the Standardization of Time Advanced in America, Dec 19, 2016, Smithsonian, https://www.smithsonianmag.com/smithsonian-institution/how-standardization-time-changed-american-society-180961503/

Buckle, Ann, Why Do We have Time Zones, timeanddate, https://www.timeanddate.com/time/time-zones-history.html

[22] Disturnell, John, Disturnell’s railroad, steamboat and telegraph book being a guide through the United States and Canada : also giving the ocean steam packet arrangements, telegraph lines and charges, list of hotels, &c. : with a map of the United States and Canada showing all the canals, railroads, &c, July 1851, New York: J. Disturnell, Page 43, https://catalog.hathitrust.org/Record/100280015/Home

For a fairly complete list of John Distunrell’s books, see: Online Books by John Disturnell, https://onlinebooks.library.upenn.edu/webbin/book/lookupname?key=Disturnell%2C%20John%2C%201801%2D1877

[23] Ibid, Page One

[24] Paris-Est–Strasbourg-Ville railway, Wikipedia, This page was last edited on 14 June 2022, https://en.wikipedia.org/wiki/Paris-Est–Strasbourg-Ville_railway

Direction Générale des Ponts et Chaussées et des Chemins de Fer, Statistique centrale des chemins de fer. Chemins de fer français. Situation au 31 décembre 1869 (in French). Paris: Ministère des Travaux Publics, 1869, pp. 146–160

[25] Atack, Jeremy & Bateman, Fred & Margo, Robert. The Transportation Revolution Revisited: Towards a New Mapping of America’s Transportation Network in the 19th Century. Uploaded 12 Jan 2015, preliminary paper, ResearchGate,  Page 15, https://www.researchgate.net/figure/The-Railroad-Network-in-1850-1860-1870-and-1880-Mapped-Against-1860_fig3_267239718

[26] Modified version of Map originally from ULamm, France1860railways.png, 24 Aug 2009, Wikimedia Commons, This page was last edited on 8 June 2022 , https://commons.wikimedia.org/wiki/File:France1860railways.png

[27] The map is a portion of the map: Figure 3-bis: Postal roads and main cities and towns in 1833 in Verdier, Micolas and Anne Bretagnolle. Expanding the Network of Postal Routes in France 1708-1833. histoire des réseaux postaux en Europe du XVIIIe au XXIe siècle, May 2007, Paris, France. pp.159 – 175. https://shs.hal.science/halshs-00144669/document

[28] Boyd, James D., An Investigation into the Structural Causes of German-American Mass Migration in the Nineteenth Century, Submitted for the award of PhD, History, Cardiff University 2013, Page 123 https://orca.cardiff.ac.uk/id/eprint/47612/1/2013boydjdphd.pdf

[29] Mark R. Stoneman, “An 1853 Map for German-Speaking Emigrants,” Migrant Knowledge, January 30, 2022, https://migrantknowledge.org/2022/01/30/an-1853-map-for-german-speaking-emigrants/

[30] Atack, Jeremy & Bateman, Fred & Margo, Robert. The Transportation Revolution Revisited: Towards a New Mapping of America’s Transportation Network in the 19th Century. Uploaded 12 Jan 2015, preliminary paper, ResearchGate, Page 20  https://www.researchgate.net/figure/The-Railroad-Network-in-1850-1860-1870-and-1880-Mapped-Against-1860_fig3_267239718

[31] Page, Thomas W. “The Transportation of Immigrants and Reception Arrangements in the Nineteenth Century.” Journal of Political Economy, vol. 19, no. 9, 1911, pp. 736. JSTORhttp://www.jstor.org/stable/1820349

[32] German Americans, Wikipedia, This page was last edited on 17 May 2024, https://en.wikipedia.org/wiki/German_Americans

[33] Maine nor New Hampshire were top destinations. There were a couple notable German immigrant communities established there by the mid-1800s, especially in Waldoboro, Maine which retained its German heritage. Between 1740 and 1753, approximately 1,500 Germans immigrated to what was then known as Broad Bay Plantation (now Waldoboro, Maine). They were recruited by Samuel Waldo with promises of land, funding, and freedom.

By the mid-1800s, Waldoboro was one of the only two named German settlements in Maine according to Traugott Bromme’s emigrant guidebook, the other being Biddeford. In addition to Waldoboro, some other Maine towns were named after German hometowns by early settlers, such as Hanover, Bremen, and Dresden.

German Jews also immigrated to Maine, arriving in Bangor as early as 1829 and establishing the Bangor Hebrew Center in 1839. The Congregation Ahawas Achim was founded there in 1849.

Bland, L., Traugott Bromme and the State of Maine, Maine History, Jan 1 2015, Volume 49, Number ! The Maine Melting Pot, Page 102 – 112, https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1126&context=mainehistoryjournal

The Germans of Waldoboro, Meander Maine, https://meandermaine.com/tale/the-germans-of-waldoboro/

German Americans, Wikipedia, This page was last edited on 17 May 2024, https://en.wikipedia.org/wiki/German_Americans

Welcome to Documenting Maine Jewry, a collaborative history and genealogy of Maine’s vibrant Jewish communities, https://mainejews.org

Maine Historical Society, Copy of a plan of lands on the west side of Madomack River, Waldoboro, 1774, Maine Memory Network, https://www.mainememory.net/record/102767

400 Years Waldo Patent and German immigrants, Maine Memory Network, https://www.mainememory.net/sitebuilder/site/2623/slideshow/1635/display?format=list&prev_object=page&prev_object_id=4227&use_mmn=1

Thompson, Garret W., The Germans in Maine (Waldoboro’, Lincoln County, Maine), http://files.usgwarchives.net/me/lincoln/waldoboro/settlers/german/sj5p140.txt

[34] Disturnell’s New Map of the United States and Canada Showing all the Canals, Rails Roads, Telegraph Lines and principal Stage Routes, Drawn by Henry A Burr, New York: J. Disturnell, 1850, Online Library of Congress: https://www.loc.gov/item/98685344/

Disturnell’s 1850 Map

[35] The map is a blown up portion of “Disturnell’s New Map of the United States and Canada” that focuses on Vermont, New Hampshire, and Maine. I have added the legend from the original map to provide an idea of what each of the types of lines represent. I have also indicated where each of the towns that Zimmermann identified in his map are located on Disturnell’s map.

Other American Maps that can be used to provide comparisons with Zimmermann’s map are mentioned below. Distunell’s map, however, is a excellent map to utilize since it portrays road, rail and waterways.:

Historic Railroad Map Of The Northeastern United States – 1853 https://www.worldmapsonline.com/historic-railroad-map-of-the-northeastern-united-states-1853

Goldthwait, J. H., Railroad map of New England & eastern New York complied from the most authentic sources, Boston : Redding & Co. ; New York : Clark, Austin & Co., 1849, Library of Congress, Library of Congress Control Number 98688377, https://lccn.loc.gov/98688377

Snow & Wilder, Hitchcock, DeWitt C., Map of railways in New England and part of New York; Boston, [1847] engraved by D. C. Hitchcock for the Pathfinder Railway Guide, Library of Congress Control Number 98688376, Library of Congress, https://lccn.loc.gov/98688376

[36] Rudolph Vecoli, European Americans: From Immigrants to Ethnics, Section I : Immigrants, Ethnics, Americans, Cleveland Ethnic Heritage Studies, Press Books, Cleveland State University 1976. https://pressbooks.ulib.csuohio.edu/ethnicity/chapter/european-americans-from-immigrants-to-ethnics/

James Boyd in his Introduction to his PhD Dissertation , The Limits to Structural Explanation, provides a good overview of the historical approaches that have been used for explaining German migration to America, see: 

James D. Boyd, An Investigation into the Structural Causes of German-American Mass Migration in the Nineteenth Century, Submitted for the award of PhD, History, Cardiff University 2013, https://orca.cardiff.ac.uk/id/eprint/47612/1/2013boydjdphd.pdf

Helbich, Wolfgang. “German Research on German Migration to the United States.” Amerikastudien / American Studies, vol. 54, no. 3, 2009, pp. 383–404. JSTORhttp://www.jstor.org/stable/41158447

Günter Moltmann, “Migrations from Germany to North America: New Perspectives.” Reviews in American History, vol. 14, no. 4, 1986, pp. 580–96. JSTORhttps://doi.org/10.2307/2702202

Marianne S. Wokeck, Trade in Strangers: The Beginnings of Mass Migration to North America, University Park: Pennsylvania State University Press, 1999

Häberlein, Mark. “German Migrants in Colonial Pennsylvania: Resources, Opportunities, and Experience.” The William and Mary Quarterly, vol. 50, no. 3, 1993, pp. 555–74. JSTORhttps://doi.org/10.2307/2947366

Philip Otterness, Becoming German, The 1709 Palatine Migration to New York, Ithaca: Cornell University Press, 2004

Donna Merwick, Possessing Albany, 1630-1710: The Dutch and English Experiences, Cambridge, 1990

Thomas Burke, Mohawk Frontier: The Dutch Community of Schenectady, New York 1660-1710, Ithaca, 1991, Page 213

Natalie Zemon Dennis, Cultivating a Landscape of Peace: Iroquois-European Encounters in the Seventeenth-century America, Ithaca, 1993

Francis Jennings, Ambiguous Iroquois Empire, New York, 1984

The Palatine Germans, The National Park Service, Updated October 8, 2022 https://www.nps.gov/articles/000/the-palatine-germans.htm

Aaron Spencer Fogleman, Hopeful Journeys: German Immigration, Settlement and Political Culture in Colonial America, 1717-1775, Philadelphia: University of pennsylvania Press 1996

Philip Otterness, Becoming German, The 1709 Palatine Migration to New York,Ithaca: Cornell University Press, 2004

Cobb, Sanford Hoadley. The Story of the Palatines: An Episode in Colonial History. United Kingdom, G. P. Putnam’s sons, 1897. https://www.google.com/books/edition/The_Story_of_the_Palatines/eUgjAAAAMAAJ?hl=en

Brink, Benjamin Myer. “The Palatine Settlements” Proceedings of the New York State Historical Association, vol. 11, 1912, pp. 136–43. JSTOR, http://www.jstor.org/stable/42889955. Accessed 27 May 2023.

Ellsworth, Wolcott Webster. “The Palatines in the Mohawk Valley.” Proceedings of the New York State Historical Association, vol. 14, 1915, pp. 295–311. JSTOR, http://www.jstor.org/stable/42890044. Accessed 27 May 2023.

Diefendorf, Mary Riggs. The Historic Mohawk. United Kingdom, Putnam, 1910. https://www.google.com/books/edition/The_Historic_Mohawk/ziIVAAAAYAAJ?hl=en

Benton, Nathaniel Soley. A History of Herkimer County: Including the Upper Mohawk Valley, from the Earliest Period to the Present Time ; with a Brief Notice of the Iroquois Indians, the Early German Tribes, the Palatine Immigrations Into the Colony of New York, and Biographical Sketches of the Palatine Families, the Patentees of Burnetsfield in the Year 1725 ; and Also Biographical Notices of the Most Prominent Public Men of the County ; with Important Statistical Information. United States, J. Munsell, 1856. https://www.google.com/books/edition/A_History_of_Herkimer_County/G1IOAAAAIAAJ?hl=en

[37] Burnett and Ken Luebbering, German Settlement in Missouri: New Land, Old Ways, Columbia: University of Missouri Press, 1996

[38] Hungerford, Edward. “Early railroads of New York” New York History, vol. 13, no. 1, 1932, pp. 75–89. JSTOR, http://www.jstor.org/stable/24469729 

Ellis, David Maldwyn, “Rivalry between the New York central and the Erie Canal” New York History, vol. 29, no. 3, 1948, pp. 268–300. JSTOR, http://www.jstor.org/stable/43460288 

Rapp, Marvin A., “New York’s Trade on the Great Lakes, 1800 -1840.” New York History, vol. 39, no. 1, 1958, pp. 22–33. JSTOR, http://www.jstor.org/stable/23153562 

Fairlie, John A. “The New York Canals.” The Quarterly Journal of Economics, vol. 14, no. 2, 1900, pp. 212–39. JSTOR, https://doi.org/10.2307/1883769 

North, Edward P. “The Erie Canal and Transportation.” The North American Review, vol. 170, no. 518, 1900, pp. 121–33. JSTOR, http://www.jstor.org/stable/25104942 

Whitford, Noble E. “Effects of the Erie Canal on New York History.” The Quarterly Journal of the New York State Historical Association, vol. 7, no. 2, 1926, pp. 84–95. JSTOR, http://www.jstor.org/stable/43566182 

Jackson, Harry F., “The Erie Canal.” Scholar in the Wilderness: Francis Adrian Van Der Kemp, Syracuse University Press, 1963, pp. 268–82. JSTOR, https://doi.org/10.2307/j.ctv64h7kc.25 

Shaw, Ronald E. “Canals in the Early Republic: A Review of Recent Literature.” Journal of the Early Republic, vol. 4, no. 2, 1984, pp. 117–42. JSTOR, https://doi.org/10.2307/3122718

Burd, Camden. “A New, Historic Canal: The Making of an Erie Canal Heritage Landscape.” IA. The Journal of the Society for Industrial Archeology, vol. 42, no. 2, 2016, pp. 23–34. JSTOR, https://www.jstor.org/stable/26643089

[39] Gerlach, Russel, The German Presence in the Ozarks, OzarksWatch, Vol III, No.1, Summer 1989, https://thelibrary.org/lochist/periodicals/ozarkswatch/ow301h.htm Page, Thomas W. “The Transportation of Immigrants and Reception Arrangements in the Nineteenth Century.” Journal of Political Economy, vol. 19, no. 9, 1911, pp. 736. JSTORhttp://www.jstor.org/stable/1820349 .

Reinhard Wittmann, Ein Verlag und seine Geschichte: Dreihundert Jahre J. B. Metzler Stuttgart (Stuttgart: J. B. Metzlersche Verlagsbuchhandlung, 1982), 411. 

Dolindel, Sonja, , Off to New York ! A story of immigration in the 19th century in pictures, 16.12.2021, Kultur und Wissen online, Deutsche Digitale Bibliothek, https://www.deutsche-digitale-bibliothek.de/content/blog/ab-nach-new-york-eine-geschichte-der-auswanderung-im-19-jahrhundert-bildern?lang=en

Zimmermann, Gotthelf. Auswanderer-Karte und Wegweiser nach Nordamerika. Stuttgart: J.B. Metzler’schen Buchh, 1853. Map. https://www.loc.gov/item/98687132/ 

[40] Dahmann, Donald C., Presenting the Nation’s Cultural Geography, General Maps Collection, Articles and Essays, Nationals Atlases. Library of Congress, https://web.archive.org/web/20201109045038/https://www.loc.gov/collections/general-maps/articles-and-essays/national-atlases/presenting-the-nations-cultural-georgraphy/

[41] Ibid, Dahmann, Donald C., Presenting the Nation’s Cultural Geography

[42] A. de Witzleben, German Population 9th Census, Page 325, in Francis A Walker, Superintendent of Census, Ninth census – Volume I,  The Statistics of the Population of the United States, Washington, Government Printing Office, 1872 https://www.google.com/books/edition/Ninth_Census_volumes/0ngZm56S-7sC?hl=en&gbpv=1

For a 1890 version, see: Gannett, Henry, 50. Density of Distribution of the Natives of the Germanic Nations, Plate 20, Statistical atlas of the United States, based upon the results of the eleventh census, United States. Census office. 11th census, 1890 https://www.loc.gov/resource/g3701gm.gct00010/?sp=40

[43] The “German belt” refers to the region of the United States where large numbers of German immigrants settled in the 19th century, especially from the 1840s to early 1900s. This area stretched from Pennsylvania across the Midwest to the Great Plains states. It included states like Pennsylvania, Ohio, Indiana, Illinois, Wisconsin, Minnesota, Iowa, Missouri, Nebraska, Kansas, and parts of the Dakotas. The highest concentrations were in the Upper Midwest.

[44] Midwestern United States, Wikipedia, This page was last edited on 15 May 2024, https://en.wikipedia.org/wiki/Midwestern_United_States

[45] Kamphoefner, Walter, The German Component to American Industrialization, Jan 27, 2014, Immigrant Entrepreneurship: 1720 to the Present, , German Historical Institute, http://www.immigrantentrepreneurship.org/entries/the-german-component-to-american-industrialization/

Bergquist, James M. “German Communities in American Cities: An Interpretation of the Nineteenth-Century Experience.” Journal of American Ethnic History, vol. 4, no. 1, 1984, pp. 9–30. JSTOR, http://www.jstor.org/stable/27500350

[46] Schulten, Susan ,A History of America in 100 Maps, Chicago: The University of Chicago Press, 2018, Page 8