Formation period of the transatlantic slave trade system

Timeline

1. c. 1500–1520São Tomé and Príncipe · São ToméIn the early 16th century Portugal established sugarcane plantations on São Tomé, purchasing African slaves from the Congo and Guinea coasts for production, forming an early Atlantic forced labor model of 'island plantation—African procurement—European capital', providing an institutional template for later large-scale replication in the Americas.
2. 1521–1530Gulf of Guinea to the Caribbean · AtlanticBetween 1521 and 1530, Portuguese and Castilian colonies expanded African labor imports in Hispaniola, Cuba, and Brazil; royal charters (predecessors of the asiento) and a system of port agents were initially established, with slave ships regularly departing from the Gold Coast, Benin, and the Congo River mouth, making transatlantic forced population movement a routine supply for the colonial economy.
3. 1530–1600Europe–Africa–Americas triangular sea lanes · AmericasAfter the 1530s, the triangular cycle of European manufactured goods exchanged in West Africa for slaves, slaves shipped to the Americas for commodities, and then returned to Europe gradually took shape; although the Church and the crown occasionally debated restrictions, demand from the plantation economy gave the system sustained momentum for expansion at both legal and commercial levels.