The Atlantic Slave Trade and the Middle Passage

The trade ran as a triangular circuit. Ships left European ports loaded with manufactured goods like guns, cloth and alcohol, traded them on the West African coast for captives, then crossed the Atlantic on the Middle Passage, the voyage's brutal middle leg. That crossing took six to eight weeks, with people chained below deck in spaces too low to stand in, fed little, and exposed to dysentery and smallpox. Roughly ten to twenty percent died at sea, a loss shippers treated as a routine cost of doing business, not a tragedy to prevent. Ships then sold survivors in the Americas and sailed home carrying sugar, tobacco and other goods, completing the loop and funding the next voyage.

Where captives landed depended on what labor the destination demanded. Sugar cultivation in Brazil and the Caribbean killed workers so fast, through overwork, tropical disease and violent discipline, that planters needed a constant stream of new arrivals just to maintain their workforce. That single fact explains why those regions absorbed the overwhelming majority of the 12.5 million people carried out of Africa, while under five percent came directly to the mainland colonies that became the United States. North America's enslaved population grew differently: smaller farms, a less lethal disease environment, and more balanced sex ratios let the population expand through births rather than constant importation.

This topic sets up what follows: how slavery hardened into a legal, hereditary racial system on the mainland even as direct imports stayed comparatively small. The demand curve also shifts after 1700, as mainland tobacco and rice plantations expand and pull in far more direct shipments than in the 1600s, feeding the slave codes and racial hierarchy that follow.