Spain’s involvement in the trans-Atlantic slave trade began in the early 16th century. Spanish traders primarily transported slaves from West Africa, including regions that are now Senegal, Gambia, and Ghana. An estimated 1.6 million Africans were shipped to Spanish colonies in the Caribbean, Mexico, Central America, and South America, including the territories of present-day Cuba, the Dominican Republic, Puerto Rico, and Peru. The labor of enslaved Africans was integral to Spain’s colonial economies, especially in silver mining and sugar plantations. The Spanish Crown regulated the trade through a system of licenses known as “asientos,” granted to private merchants. Spain formally abolished slavery in its colonies in 1817, but it wasn’t effectively enforced until the late 19th century, with Cuba being one of the last territories to abolish slavery in 1886.