The genetic legacy of African Americans from Catoctin Furnace.

Few African Americans have been able to trace family lineages back to ancestors who died before the 1870 United States Census, the first in which all Black people were listed by name. We analyzed 27 individuals from Maryland's Catoctin Furnace African American Cemetery (1774-1850), identifying 41,799 genetic relatives among consenting research participants in 23andMe, Inc.'s genetic database. One of the highest concentrations of close relatives is in Maryland, suggesting that descendants of the Catoctin individuals remain in the area. We find that many of the Catoctin individuals derived African ancestry from the Wolof or Kongo groups and European ancestry from Great Britain and Ireland. This study demonstrates the power of joint analysis of historical DNA and large datasets generated through direct-to-consumer ancestry testing.

Historical genomes elucidate European settlement and the African diaspora in Delaware.

The 17th-century colonization of North America brought thousands of Europeans to Indigenous lands in the Delaware region, which comprises the eastern boundary of the Chesapeake Bay in what is now the Mid-Atlantic region of the United States.1 The demographic features of these initial colonial migrations are not uniformly characterized, with Europeans and European-Americans migrating to the Delaware area from other countries and neighboring colonies as single persons or in family units of free persons, indentured servants, or tenant farmers.2 European colonizers also instituted a system of racialized slavery through which they forcibly transported thousands of Africans to the Chesapeake region. Historical information about African-descended individuals in the Delaware region is limited, with a population estimate of less than 500 persons by 1700 CE.3,4 To shed light on the population histories of this period, we analyzed low-coverage genomes of 11 individuals from the Avery's Rest archaeological site (circa 1675-1725 CE), located in Delaware. Previous osteological and mitochondrial DNA (mtDNA) sequence analyses showed a southern group of eight individuals of European maternal descent, buried 15-20 feet from a northern group of three individuals of African maternal descent.5 Autosomal results further illuminate genomic similarities to Northwestern European reference populations or West and West-Central African reference populations, respectively. We also identify three generations of maternal kin of European ancestry and a paternal parent-offspring relationship between an adult and child of African ancestry. These findings expand our understanding of the origins and familial relationships in late 17th and early 18th century North America.

Stable isotopes from the African site of Elmina, Ghana and their usefulness in tracking the provenance of enslaved individuals in 18th- and 19th-century North American populations.

OBJECTIVES: Stable isotope values for historic period human remains from Elmina, Ghana, are compared to isotope data from 18th- and 19th-century North American sites as a test case for examining African origins and identifying first generation Africans in the Mid-Atlantic region of the United States. MATERIALS AND METHODS: Stable carbon, nitrogen, and oxygen isotope values were measured in skeletal remains. Values from the cosmopolitan port city of Elmina provide the first available reference data from Africa during this time period and region. These values serve as a proxy for West African groups in general which are statistically compared to Euro-Americans and African Americans. RESULTS: Elmina carbon isotope values are relatively higher than those of North Americans, and African Americans show greater statistical similarity to West Africans. Elmina nitrogen isotope values are higher than those of North Americans. Elmina oxygen isotope values are notably higher than those in all Mid-Atlantic North American sites in this study. DISCUSSION: Similarity in carbon isotope values between Elmina and African Americans suggests commonalities in food availability or food preferences between these groups. Elevated nitrogen isotope values in Elmina individuals support the documented reliance of the local population on marine dietary resources at this coastal port. While carbon and nitrogen isotopes provide insight into foodways, oxygen isotope data, sourced from drinking water, provide better geographical information. The higher oxygen values from Elmina not only differentiate this group from North American Mid-Atlantic sites, but also make it possible to identify outliers at these sites as potential recent arrivals from West Africa.

Ancient DNA and bioarchaeological perspectives on European and African diversity and relationships on the colonial Delaware frontier.

OBJECTIVES: Ancient DNA (aDNA) and standard osteological analyses applied to 11 skeletons at a late 17th to early 18th century farmstead site in Delaware to investigate the biological and social factors of settlement and slavery in colonial America. MATERIALS AND METHODS: Osteological analysis and mitochondrial DNA (mtDNA) sequencing were conducted for all individuals and the resulting data contextualized with archaeological and documentary evidence. RESULTS: Individuals of European and African descent were spatially separated in this colonial cemetery. The skeletal remains exhibited differences in osteological features and maternal genetic ancestry. A specific mtDNA haplotype appeared in a subset of the European-descended individuals suggesting they were maternally related. Individuals of African descent were not maternally related, and instead showed a diversity of haplotypes affiliated with present-day Western, Central, and Eastern regions of Africa. DISCUSSION: Along with the bioarchaeological and documentary evidence, the aDNA findings contribute to our understanding of life on the colonial Delaware frontier. Evidence of maternal relatedness among European-descended individuals at the site demonstrates kin-based settlements in 17th century Delaware and provides preliminary identifications of individuals. The maternal genetic diversity of the individuals with African descent aligns with the routes of the trans-Atlantic slave trade but broadens our understanding of the ancestries of persons involved in it. Burial positioning, osteological pathology, and lack of maternal kinship among individuals of African descent provide tangible evidence for the emergence of racialized labor and society in Delaware during the late 17th century.