Well, some tribes owned slaves. Im sure they were treated better then the slaves owned by Europeans but still, they owned slaves so im sure many tribes are pieces of shyt.
Pre-contact forms of slavery were generally distinct from the form of
chattel slavery developed by Europeans in North America during the colonial period. European influence greatly changed slavery used by
Native Americans. As they raided other tribes to capture slaves for sales to Europeans, they fell into destructive wars among themselves, and against Europeans.
Many Native American tribes practiced some form of slavery before the European introduction of African slavery into North America; but none exploited slave labor on a large scale.
Native American groups often enslaved
war captives whom they primarily used for small-scale labor.
European colonists caused a change in Native American slavery, as they created a new demand market for captives of raids. For decades, the colonies were short of workers. Especially in the southern colonies, initially developed for resource exploitation rather than settlement, colonists purchased or captured Native Americans to be used as forced labor in cultivating tobacco, and, by the eighteenth century, rice, and indigo. To acquire trade goods, Native Americans began selling war captives to whites rather than integrating them into their own societies.
Slave traders preferred captive Native Americans who were under eighteen years old, as they were believed to be more easily trained to new work.In the Illinois Country, French colonists baptized as Catholics Native American slaves whom they bought for labor.
They believed it essential to convert Native Americans to the Catholic faith. (I wonder why)Church baptismal records have thousands of entries for Indian slaves.
In the Spanish colonies,
the church assigned Spanish surnames to Native Americans and recorded them as servants rather than slaves.
In the early colonial days, Native Americans were enslaved along with Africans, and both often worked with European
indentured laborers. "They worked together, lived together in communal quarters, produced collective recipes for food, shared herbal remedies, myths and legends, and in the end they intermarried."
Because both races were non-Christian, Europeans considered them other and inferior to Europeans. They worked to make enemies of the two groups. In some areas, Native Americans began to slowly absorb white culture. 
Benjamin Hawkins, (TALK about a demonic muthafukker ) Superintendent of the tribes south of the Ohio River from the late eighteenth century through the early nineteenth, encouraged the major Southeast tribes to adopt
chattel slavery in order to have labor for plantations and large-scale agricultural production, as part of their
assimilation of European-American ways.The
Five Civilized Tribes adopted some practices which they saw as beneficial;
they were working to get along with the Americans and to keep their territory.
I have some books that talk about what CAC referred to as the Five Civilized Tribes.... that gets deeper.. but wiki surprising crushes the tip of the ice.
