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.