6317568 African slave traffic by Unknown Artist, (19th century); (add.info.: African slave traffic. One group of Africans sell other Africans to white slave traders. From The History of Slavery and the Slave Trade - Ancient and Modern - The Forms of Slavery that Prevailed in Ancient Nations, Particularly in Greece and Rome. By W. O. Blake. Published in Columbus, Ohio, USA, 1859); Photo by Ken Welsh; out of copyright.