During the 18th century vast numbers of Africans were shipped across the Atlantic to become slaves on the sugar and cotton plantations of North America and the Caribbean. Much of this trade was controlled by the British, whose ships sailed from Bristol and other ports to West Africa loaded with manufactured goods which were bartered for slaves. This human cargo crossed the Atlantic to the New World, where the surviving slaves were sold and replaced as cargo by tobacco, sugar, and cotton, materials required back in Europe.
The so-called “Triangular Trade” was one of the bedrocks of British prosperity in the period and many of the wealthiest families owed much to their involvement with the profits from the trade. By the end of the century, however, there was increasing opposition to the slave trade and movements for its abolition were established. Many of the most prominent individuals in North America, such as George Washington, were personally opposed to slavery, although there was little coordination amongst these individuals to obtain abolition. Often these individuals—again, as George Washington—were to free their slaves in their wills, but this affected a fraction of the estimated 250,000 slaves that existed within the Thirteen Colonies before Independence.