I am taking a history course focusing on American history and was to curious as to why Native tribes did not side with the African slaves to abolish slavery. Both had a common interest, blacks were being enslaved and Natives were having their land taken from them. From my understanding, Natives weren't enslaved and had the means to go to wsr if needed.
I will copy/paste an answer I gave to this type of question a while back. If you want any more than this, let me know:
I'll write primarily on the Cherokee relationship with African slavery (and slavery in general), since that has been my primary area of research on this subject. By the mid-eighteenth century, some Cherokees had begun to demonstrate some of the same racial attitudes toward slavery that had previously been utilized by the whites that shared their continent. Not only the acceptance of slavery, but also structured Christianity, functional capitalism, general government, and other methods of living such as dress, diet, and agriculture, began to seep into the Cherokee Nation. Not all Cherokees, however, embraced white acculturation. These ways of white men were much more readily accepted by the leaders of the Cherokee and especially those Cherokee men with even small amounts of white blood in them. These Cherokee leaders that acknowledged and incorporated assimilation into white culture were not a large fraction of the total Cherokee population, barely the top few percent, but they held enough power over policymaking that their influence and ultimate decision to try to acculturate caused major problems within the Nation. The internal rife triggered by the existential problems produced by attempted white assimilation of Cherokee leaders led to the necessary conditions for conquest by the United States. Many members of the Chickasaw, Choctaw, Creek, and Seminole were active participants in the institution of black slavery, in addition to the Cherokee. Historians have estimated that thousands of black slaves were owned by these five southern, “civilized” tribes. General slavery predates black slavery among the Cherokee. Prior to the Cherokee being very active in the black slave trade, many Cherokee warriors had carried on the practice of enslaving prisoners of war and selling them to other tribes or European traders for manufactured goods. When the British began to seek out free, non-indentured labor, the demand for Cherokee captives became quite high. The act of gaining a lot of material goods through human trafficking began the process of the changing attitude toward race and slavery among the Cherokee. "Slavery" was also quite different in Cherokee society, as slaves of all color were oftentimes able to become accepted into the Cherokee family and abandon their "slave" status. I cannot stress enough, however, that the split between traditional, full blooded Cherokee (and their rejection of African slavery) and "progressive", mixed blooded Cherokee (and their insistence upon African slavery as a means of white acculturation) was a major cause of the demise of the Cherokee Nation. I'd be glad to write you more on the institution of Cherokee slavery, in general, if you'd like. The southern tribes had an interesting way of dealing with slavery among each other prior to European contact.
There is far too much diversity between native American tribes to really make any sort of generalized statements.
For example, in the narrative of Cabeza de Vaca, we see several wildly different reactions to African slaves by several different native groups. The general gist of the story is that Cabeza is shipwrecked and stranded in the lower eastern area of north America for about 9 years.
In one case, he mentions that a few members of a particular native group appear as if they were Africans. They were likely adopted. In another case, he and an African slave are stranded together and are themselves enslaved (though he never uses the term itself, they are forced to work and not allowed to leave) by a native tribe. And in yet another example, he mentions a group of slaves who escaped from a Spanish colony only to be massacred by the natives they later encountered. The differences between various native tribes are huge, and their culture and reaction to prisoners and/or individuals they happen across cannot be examined at all through western logic.
Finally, as to why there was no real unity or alliance towards the white settlers until it was too late, the analogy that is most fitting in my opinion is that of our attitudes towards global warming. Despite evidence that these settlers are a problem, (they take land, make war on occasion, and have a horrid habit of breaking treaties), and are rapidly growing in population, any sort of united war against them would be inconvenient. The natives have begun to rely on European goods, enjoy trade, and don't really feel the need to work with their historical enemies against a common foe. And besides, the Europeans probably won't be a problem for many many years. It would take a major change of way of life to do something about it.
And by the time they did make attempts to unite and do something about it, it was far too late.