Slavery in Brazil began long before the first Portuguese settlement was established in 1532, as members of one tribe would enslave captured members of another.
Later, colonists were heavily dependent on indigenous labor during the initial phases of settlement to maintain the subsistence economy, and natives were often captured by expeditions called bandeiras, originating in São Paulo. The importation of African slaves began midway through the 16th century, but the enslavement of indigenous peoples continued well into the 17th and 18th centuries.
During the Atlantic slave trade era, Brazil imported more African slaves than any other country. An estimated 4.9 million slaves from Africa came to Brazil during the period from 1501 to 1866. Until the early 1850s, most enslaved Africans who arrived on Brazilian shores were forced to embark at West Central African ports, especially in Luanda (present-day Angola). Today, with the exception of Nigeria, the largest population of people of African descent is in Brazil.
Slave labor was the driving force behind the growth of the sugar economy in Brazil, and sugar was the primary export of the colony from 1600–1650. Gold and diamond deposits were discovered in Brazil in 1690, which sparked an increase in the importation of African slaves to power this newly profitable market. Transportation systems were developed for the mining infrastructure, and population boomed from immigrants seeking to take part in gold and diamond mining.
Demand for African slaves did not wane after the decline of the mining industry in the second half of the 18th century. Cattle ranching and foodstuff production proliferated after the population growth, both of which relied heavily on slave labor. 1.7 million slaves were imported to Brazil from Africa from 1700 to 1800, and the rise of coffee in the 1830s further enticed expansion of the slave trade.
Brazil was the last country in the Western world to abolish slavery. By the time it was abolished, in 1888, an estimated four million slaves had been imported from Africa to Brazil, 40% of the total number of slaves brought to the Americas.
Read more on this via the source url below.