Annual number of African slaves taken by each European nation 1501-1866

Portuguese and Brazilian traders were responsible for transporting the highest volume of slaves during the transatlantic slave trade. Portugal held a near-monopoly on the transatlantic slave trade in the 16^th century, due to their network of factories along the African coast, and also imported hundreds of thousands of slaves into Brazil and the Caribbean in the 19^th century.

Emergence of other powers

The rise of the British, French and Dutch empires in the 17^th century was also fueled by profits made from slave labor, and, to a lesser extent, the slave trade. Throughout the 1700s especially, British ships transported more slaves across the Atlantic, as the empire expanded across the Caribbean and North America. Similarly to Britain, ships flying under the flag of the Thirteen Colonies or the U.S. saw relatively large growth from the mid-1700s onwards (apart from a brief disruption caused by the American Revolutionary War), with the number of slave imports peaking in the early years of the 1800s. However, both Britain and the U.S. abolished the slave trade in 1807 and 1808 respectively, which ended their official participation in the widespread importation of slaves. French imports of slaves peaked in the late 1780s, however the numbers then plummeted from 1790 onwards, due to the instability and turmoil caused by the French Revolution and Haitian Revolution.

The largest empire was one of the smallest slave importers

While a significant number of slaves eventually ended up in the Spanish Americas, Spanish merchants did not explicitly transport slaves in the same quantities as other powers' merchants. The was rooted in the Spanish legacy of importing slaves through foreign powers (namely Portugal, largely due to the Treaty of Tordesillas), and the forced labor of indigenous societies. However this changed drastically in the 19^th century, as independence movements swept across Spain's mainland colonies in the Americas, and Spain then invested heavily into its Caribbean colonies (particularly Cuba).