In the early 1830s, the Portuguese government appointed a progressive prime minister, the Marquês de Sá da Bandeira, whose most important reform was the abolition of the slave trade in 1836. The decree, however, could not be enforced adequately, and it took Britain's Royal Navy to put an end to the activity in the middle of the nineteenth century.

In 1858 slavery was legally abolished in Angola. Government slaves had already been freed in 1854, but the 1858 proclamation declared that all slavery should cease by 1878. Legislation was passed to compensate owners and to care for the freed people. But many of the colonists found ways to circumvent the decree, so that the actual conditions of labor did not change significantly.

Data as of February 1989