Slavery among Native Americans in the United States includes slavery by and slavery of Native Americans roughly within what is currently the United States of America. Tribal territories and the slave trade ranged over present-day borders. Some Native American tribes held war captives as slaves prior to and during European colonization. Some Native Americans were captured and sold by others into slavery to Europeans, while others were captured and sold by Europeans themselves. In the late 18th and 19th centuries, a small number of tribes adopted the practice of holding slaves as chattel property, holding increasing numbers of African-American slaves.