Which of the major components of the Atlantic world — the Americas, Africa, and Europe — was most immediately affected by the integration of the Old and New Worlds that Columbian contact triggered? On epidemiological grounds alone the Americas would be the choice of most scholars, with Europe, at least prior to the eighteenth century, the least affected. In terms of dramatic economic, demographic, and social consequences of the early stages of Atlantic integration, Africa lies somewhere between the two. Yet if we shift the focus to changes in the nature and size of connections between the continents as opposed to changes within them, the most striking developments between the 1640s and the 1770s relate to Africa, not Europe or the Americas. The Slave Coast was a major supplier of slaves to transatlantic markets. West Central Africa, by far the largest supplier of slaves to the Americas, experienced two diasporas. Captives from the northern ports went to the colonies of northern Europeans, those from Luanda and Benguela in the south went to Brazil. By the end of the third quarter of the eighteenth century, the transatlantic slave trade was close to the highest level it was ever to attain.