Atlantic slavery filled a labor gap disease and conquest had opened
The Atlantic slave trade shipped enslaved Africans to the Americas on European and New World vessels, often via the triangular route’s Middle Passage. After Australia, the Americas were thinly peopled; conquest and epidemics shrank Indigenous labor, and Europeans would not meet plantation demand alone.
Portugal led in volume, followed by Britain, Spain, France, the Dutch, the United States, and Denmark. South American harbors loomed large; vessels based in the Americas may have moved more captives than fleets sailing from Europe. Currents that once blocked return trips became highways once sailors learned the wind system.
John Thornton argued technical and commercial motives made Europeans likeliest to open Atlantic commerce—seeking profit and Atlantic islands as stepping stones. Columbus-era contact launched the Columbian exchange and global silver flows; Iberian conquistadors led early waves, but French, English, Italian, and Dutch actors joined.
Current estimates put the number loaded onto ships for the Americas at about 12.75 million, of whom up to 2 million died at sea, while roughly 8 million more were enslaved and kept within Africa. Most captives came from Central and West Africa and were bought from African merchants rather than seized in European raids. The Portuguese held purchased people in barracoons at their bases, whereas northern Europeans often used the ship itself as a holding pen, prolonging confinement for the first captives aboard. The model was borrowed from the sugar plantations of Madeira and the Canaries around 1450.
In the Americas the enslaved worked sugar, cotton, tobacco, coffee and cocoa plantations, mines, rice fields, shipyards and households. Early arrivals in English colonies were classed as indentured servants, but by the mid-1600s slavery had hardened into a racial caste in which a mother's status passed to her children. Governments began banning the trade early in the nineteenth century, though smuggling persisted.
Source: Atlantic slave trade
