They've traced the first boatload of slaves to Angola.
Quote from the article:
Virginia's first Africans spoke Bantu languages called Kimbundu and Kikongo. Their homelands were the kingdoms of Ndongo and Kongo, regions of modern-day Angola and coastal regions of Congo. Both were conquered by the Portuguese in the 1500s. The Africans mined tar and rock salt, used shells as money and highly valued their children, holding initiation ceremonies to prepare them for adulthood.