 4 million slaves were obtained by Brazil, 1.5 million more than any other country.Starting around 1550, the Portuguese began to trade African slaves to work the sugar plantations, once the native Tupi people deteriorated.Although Portuguese Prime Minister Sebastião José de Carvalho e Melo, 1st Marquis of Pombal abolished slavery in mainland Portugal on 12 February 1761, slavery continued in her overseas colonies.