Until the middle of the 17th century, Mexico was the largest single market for slaves in Spanish America. While the Portuguese were directly involved in trading enslaved peoples to Brazil, the Spanish Empire relied on the Asiento de Negros system, awarding (Catholic) Genoese merchant bankers the license to trade enslaved people from Africa to their colonies in Spanish America. Cartagena, Veracruz, Buenos Aires, and Hispaniola received the majority of slave arrivals, mainly from Angola. This division of the slave trade between Spain and Portugal upset the British and the Dutch who invested in the British West Indies and Dutch Brazil producing sugar. After the Iberian Union fell apart, Spain prohibited Portugal from directly engaging in the slave trade as a carrier. According the Treaty of Münster the slave trade was opened for the traditional enemies of Spain, losing a large share of the trade to the Dutch, French, and English. For 150 years, Spanish transatlantic traffic was operating at trivial levels. In many years, not a single Spanish slave voyage set sail from Africa. Unlike all of their imperial competitors, the Spanish almost never delivered slaves to foreign territories. By contrast, the British, and the Dutch before them, sold slaves everywhere in the Americas.
Until the middle of the 17th century, Mexico was the largest single market for slaves in Spanish America. While the Portuguese were directly involved in trading enslaved peoples to Brazil, the Spanish Empire relied on the Asiento de Negros system awarding (Catholic) Genoese merchant bankers the license to trade enslaved people from Africa to their colonies in Spanish America. Cartagena, Veracruz, Buenos Aires, and Hispaniola received the majority of slave arrivals, mainly from Angola. This division of the slave trade between Spain and Portugal upset the British and the Dutch who invested in the British West Indies and Dutch Brazil producing sugar. After the Iberian Union fell apart, Spain prohibited Portugal from directly engaging in the slave trade as a carrier. According the Treaty of Münster the slave trade was opened for the traditional enemies of Spain, losing a large share of the trade to the Dutch, French, and English. For 150 years, Spanish transatlantic traffic was operating at trivial levels. In many years, not a single Spanish slave voyage set sail from Africa. Unlike all of their imperial competitors, the Spanish almost never delivered slaves to foreign territories. By contrast, the British, and the Dutch before them, sold slaves everywhere in the Americas.