From what ethnicity were slaves back in XIX century?

The majority of slaves held in North and South America in the 19th century were of African descent. A smaller number were also of Native American descent.

When slavery first began in the Americas in the 17th century, the majority of slaves were initially Native Americans taken captive by the Spanish and Portuguese. As disease killed more and more of the native people, slaves from Africa were imported to take their place. This practice was later adopted by English settlers. Slavery became extremely important to the agricultural economy of the American Deep South, ultimately giving rise to the American Civil War.