João’s fort immediately proved its worth. Between 1487 and 1489, 8,000 ounces of gold went from São Jorge da Mina to Lisbon; 22,500 ounces were shipped between 1494 and 1496; and by 1500, shipments totaled 26,000 ounces. Owing in large measure to the infamous papal bull that Henry had negotiated, the commerce of São Jorge da Mina soon came to include slaves as well, with ten to twelve thousand West Africans transported to Lisbon between 1500 and 1535 alone. In subsequent centuries, the fort that Columbus helped construct became one of the main export hubs of the transatlantic slave trade.
