To quote the words of freed slave Ottobah Cugoano, who was writing in the late 18th century, we find the answer: "But I my own, to the shame of my own countrymen, that I was first kidnapped and betrayed by my own complexion, who were the first cause of my exile and slavery ; but if there were no buyers there would be no sellers."
Sins of The Fathers: A Study of the Atlantic Traders 1441-1807", by James Pope-Hennessey, p. 174-5.