I have been told that when the native americans were given their land and provisions by the whites;they were a?

Provisions that they were also given african slaves and treated them just as the whites did. Being native american myself and knowing some of our history with slavery, rape, genocide and other attrocities dumped upon us by the whites..... I find it kind of hard to believe. However; Im not ignorant enough to even try and pretend I know it all, nor am I too proud to deny it happened without getting some facts first. Someone please help. It really bothers me to think that my people would do such a horrendous thing after suffering the way they did at the hands of the europeans. Thankyou!!