Slaves in Chains
"Blacks understand the concept of slavery. Their bodies withstand diseases and can work grueling hours. They are heathens and must be exposed to the goodness of the Christian realm we have created in Brazil. They don’t qualify as human, but the principles of right and wrong must be shown to them…’"

The Dawn of the Enslavement in Brazil – from 1518 to 1695

The Portuguese were involved with the African slave trade before the start of the colonization of Brazil. Scholars estimate that as many as 156,000 slaves were exported from 1441 to 1521 to Iberia and the Atlantic islands from the African coast by Portuguese slave traders. The trade made the shift from Europe to the Americas as a primary destination around 1518. Prior to this time, slaves were required to pass through Portugal to be taxed before making their way to the Americas.

Black slavery became more common in Brazil during the mid 16th century, though the enslavement of indigenous people continued into the 17th and even the 18th century in the backlands of Brazil. Nonetheless, enslaving the natives was a challenging task. They not only counted on the protection of the Jesuits, who after the proselytisation, developed an emotional bond with the Indians; they also knew the land and any escapee would make it successfully through the deeps of the jungle, their natural habitat, whereas in most of the cases, the colonists had not the proper knowledge, nor the skills to chase them. Emulating the slave labor model their deployed for many years in the islands they had conquered in Africa, Portugal exported many forced labor to its colony in America.

Enslavement of the Indigenous people
Allegedly, this is the only existing photo of a slave ship going from Africa to Brazil

During the Atlantic slave trade era, Brazil received more African slaves than any other country. An estimated 4.9 million slaves from Africa were brought to Brazil during the period from 1501 to 1866 (some estimate this number to be twice as high). 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).

Depiction of how the slaves were placed inside a hold of a slave ship and transported from Africa to the Americas
Black slaves tendering a sugarcane plantation
Black slaves working in a sugar mill

In the first half of the 16th century, Portugal divided Brazil in 15 hereditary captaincies. Each one of these parts were given to members of the Portuguese aristocracy who should manage them. From all the captaincies, only Pernambuco (in the Northeast) and São Vicente (in the Southeast) prospered, due to the sugarcane plantation and implementation of sugar mills. By this time, demand and prices of refined sugar rose because it had already replaced honey in most recipes and was increasingly used as a sweetener in jams, jellies and other popular food products. 
Slave labor was the driving force behind the growth of the sugar economy in Brazil.
The captaincy of Pernambuco had been granted to nobleman Duarte Coelho Pereira. During the Colonial Period, the captaincy of Pernambuco was the most prominent of Brazil, due to it growing sugarcane. The importance and influence of Pernambuco had become evident by mid-1550s, when the systems of hereditary captaincies had already failed and governor-general Sousa, who was assigned to oversee all of the captaincies of the colony, was not allowed to interfere in Pernambuco’s business, by  request of its donee Duarte Coelho.
By the middle of the seventeenth century the Brazilian sugar industry had begun to expand rapidly with the support of the capital from the Dutch East India Company, who seized Pernambuco from the Portuguese in 1630, and the import of slaves from equatorial Africa. In 1612 the total production of sugar in Brazil had reached 14,000 tons, and by the 1640s Pernambuco alone exported more than 24,000 tons of sugar annually to Amsterdam.

The Portuguese aristocrat Martim Afonso de Sousa is credited for being the pioneer of the sugarcane plantation. He was the donee of the Captaincy of São Vicente, who established a pattern followed by Portuguese colonizers and Brazilians for long afterward: the “entradas” and “bandeiras” – or explorations and raids into the interior – and the production of sugar along the coast for export.
Sugar became the primary export of the colony from 1600 to 1650, making Brazil the world’s leading sugar exporter. During this time, sugar accounted for 95 percent of Brazil’s exports. The slave labor was relied heavily upon to provide the workforce to maintain these profitable market. It is estimated that 560,000 Central African slaves arrived in Brazil during the 17th century in addition to the indigenous slave labor that already existed in the country.

Martim Afonso de Sousa
Slaves disembarked in Pernambuco from 1560 to 1872, TSTD2 – Trans-Atlantico Slave Trade Database
Variation rate of the Brazilian population, migration effect can be interpreted as import of slaves

A receipt for the sale of a slave named Francisca for the price of 430 milréis (equivalent today to approximately USD25,000) in September, 1818.

Recife

The city of Recife, the capital of Pernambuco was the first slave port of the Americas

Slave Auctions

Slaves were usually sold at auctions set near the ports, where slave ships arrived crammed with them. Like any other merchandise, they were inspected prior to being purchased

Senzala

A Senzala was the abode of the slave population. It was usually made with wattle and daub walls, the roof was thatched, had few windows and no partitions.

Slaves who left (1801 – 1862)*
A – Sierra Leone – 66,974
B – Gold Coast – 80,597
C – Benin Bay – 222,407
D – Biafra Bay – 217,781
E – Congo and Angola – 952,937
F – Mozambique – 236.504

* TSTD2 – Transatlantic Slave Trade Database

Slaves who arrived (1801 – 1862)*
1 – Carolina (USA) ~47 thousand
2 – Cuba – 502,998
3 – Jamaica ~69 thousand
4 – Guyana – 65,049
5 – Bahia – 161,883
6 – Southeast Brazil – 893,925