Transatlantic slave trade, segment of the global slave trade that transported between 10 million and 12 million enslaved Africans across the Atlantic Ocean to the Americas from the 16th to the 19th century. It was the second of three stages of the so-called triangular trade, in which arms, textiles, and wine were shipped from Europe to Africa, slaves from Africa to the Americas, and sugar and coffee from the Americas to Europe.
By the 1480s, Portuguese ships were already transporting Africans for use as slaves on the sugar plantations in the Cape Verde and Madeira islands in the eastern Atlantic. Spanish conquistadors took African slaves to the Caribbean after 1502, but Portuguese merchants continued to dominate the transatlantic slave trade for another century and a half, operating from their bases in the Congo-Angola area along the west coast of Africa. The Dutch became the foremost slave traders during parts of the 1600s, and in the following century English and French merchants controlled about half of the transatlantic slave trade, taking a large percentage of their human cargo from the region of West Africa between the Sénégal and Niger rivers.