When the remains of hundreds of colonial-era Africans were uncovered during a building excavation in Lower Manhattan in 1991, one coffin in particular stood out. Nailed into its wooden lid were iron tacks, 51 of which formed an enigmatic, heart-shaped design. The pattern was soon identified as the sankofa — a symbol printed on funereal garments in West Africa — and it captured the imagination of scholars, preservationists and designers. Ultimately, it was embraced by many African-Americans as a remarkable example of the survival of African customs in the face of violent subjugation in early America. The sankofa was widely...