http://www.slaveryinamerica.org/history/hs_es_indians_slavery.htmSlavery and Native Americans in British North America and the United States: 1600 to 1865
By Tony Seybert
Most Native American tribal groups practiced some form of slavery before the European introduction of African slavery into North America; but none exploited slave labor on a large scale. Indian groups frequently enslaved war captives whom they used for small-scale labor and in ritual sacrifice. Most of these so-called Indian slaves tended to live, however, on the fringes of Indian society. Although not much is known about them, there is little evidence that they were considered racially inferior to the Indians who held power over them. Nor did Indians buy and sell captives in the pre-colonial era, although they sometimes exchanged enslaved Indians with other tribes in peace gestures or in exchange for their own members. In fact, the word "slave" may not even accurately apply to these captive people.
The situation of enslaved Indians varied among the tribes. In many cases, enslaved captives were adopted into the tribes to replace warriors killed during a raid. Enslaved warriors sometimes endured mutilation or torture that could end in death as part of a grief ritual for relatives slain in battle. Some Indians cut off one foot of their captives to keep them from running away; others allowed enslaved captives to marry the widows of slain husbands. The Creek, for example, treated the children born of slaves and tribal members as full members of the tribe rather than as enslaved offspring. Some tribes held captives as hostages for payment. Other tribes practiced debt slavery or imposed slavery on tribal members who had committed crimes; but this status was only temporary as the enslaved worked off their obligations to the tribal society.
Once Europeans arrived as colonialists in North America, the nature of Indian slavery changed abruptly and dramatically. Indians found that British settlers, especially those in the southern colonies, eagerly purchased or captured Indians to use as forced labor in cultivating tobacco, rice, and indigo. More and more, Indians began selling war captives to whites rather than integrating them into their own societies. And as the demand for labor in the West Indies became insatiable, whites began to actively enslave Indians for export to the so-called "sugar islands."