Two major slave trades affected Africa. Trans-Atlantic Slave Trade (16th–19th century): enslaved West Africans transported to the Americas; Britain abolished it in 1807. East African Slave Trade: operated mainly through Zanzibar; enslaved people taken to Arabia, India, and Persia. Effects on Africa: depopulation, social disruption, wars. Zanzibar was the largest slave market in East Africa. The trade was finally abolished there in 1873 (under British pressure on Sultan Barghash).