The thing about bringing actual peoples into a fantasy world is that all of their magic and mythical creatures can take a more direct act in the game, whereas it tends to stay on the fringe in a historically-accurate game. That's where the Warlords of Erehwon game brings you all the magic and mysticism of Native Americans. We get a preview of it in this post.
From the article:
The world of Mythic Americas is awash with magic. Both the Everchanging and Everliving use magic as you and I would think of it today, and a variety of soul-based, ancient wisdom which in effect is also a type of magic, but which to us would seem more like mysticism. Both dark and light magic abounds, and the practitioners of the powerful incantations tossed around on battlefields throughout the Americas vary, they can be Shamans, Demons, Soul Walkers, Spider Sisters or even Medicine Men (who for the most part focus on healing magics, though they are no slouches at dark magic as well when pressed).