30 September 1986
Former Director of the Office of West African Affairs and Ambassador to Liberia, Edward Perkins, was appointed as the first black American ambassador to South Africa by American President Ronald Reagan. He was instrumental in efforts to end Apartheid and get Nelson Mandela out of prison. He served in this post until 1989, when he left to become the director of the US Foreign Service, a position he occupied for three years.
References

Bute, E.L. & Harmer, H.J.P. (1997). The Black Handbook, London: Cassell.|

Edward J. Perkins. 2006 Honoree [Online] available at: dom.com [Accessed 30 September 2009]