It's interesting to note that the Americas had no slavery before the Europeans and Africans came over. Before that, they just killed everyone.
I believe at least one tribe in the Pacific NW kept slaves.
The Choctaws of Mississippi actually had black slaves and allied with the Confederacy to try to keep their slaves.
Most Indian tribes did. Some slaves were eventually adopted into the tribe. Some weren't.
I went to a Mohawk pow wow in upstate New York several years ago...there were many representative of different tribes there dancing, selling artifacts and jewelry, and just hanging out. One very handsome man was an Apache from the Southwest...as he walked by a Mohawk man that I was talking to made a gutteral sound in his throat as he walked by...my friend who is 3/4 Mohawk and 1/4 Scotch said that many tribes do not like the Apache because they used to systematically kidnap women and children from other tribes and sell them into slavery in Mexico.