 In the American colonies, Portugal halted the use of Chinese, Japanese, Europeans, and Indians to work as slaves for sugar plantations, which was reserved exclusively for African slaves.The abolition of all forms of slavery occurred in 1761 on mainland Portugal and Portuguese India through a decree by the Marquis of Pombal, followed, in 1777, by Madeira.The transatlantic slave trade was definitively outlawed altogether by Portugal in 1836, at the same time as other European powers, as a result of British pressure.