Allowing for many significant variations, Native Americans, at least those west of the Mississippi River, from 1754 to 1850 witnessed a decline in political power as well as the loss of lands and the profits that came with them. In 1754, before the French and Indian War, numerous Indian polities and confederations exercised considerable power in colonial politics, usually by skillfully "playing off" the interests of Great Britain and France against each other. The most powerful of these confederations, the Iroquois Six Nations, saw their influence severely curtailed by the outcome of the French and Indian War. Indian peoples in the Ohio Valley, particularly the Shawnee and the Delaware, attempted several times to effect a pan-Indian alliance against colonial expansion, and met defeat first in Pontiac's Rebellion, then in the American Revolution and a series of frontier wars that followed, and finally in the War of 1812. Their defeat paved the way for American expansion into the Old Northwest, and most had either fled to Canada, become assimilated into white society, or driven onto reservations by 1850.
In the Southeast, the Cherokee were severely weakened by defeat in the American Revolution, while the Creek confederation fell apart under the weight of American expansion in the so-called Red Stick War. These peoples, along with the Seminoles (themselves a polyglot of Creek, escaped black slaves, and other Indian refugees over the years) the Chickasaw, and the Choctaw were removed from their lands in the 1830s, despite having accepted white customs and economic practice, including slave-owning. The Cherokee were the last of these so-called "civilized tribes" to be removed, a major policy objective of Andrew Jackson. So by 1850, most Indians east of the Mississippi River had either been driven from their lands to reservations or dissolved into white society where they either passed as white or lived as minorities.
This collection of documents looks interesting. It's bit pricy, but I bet it is full of juicy details. I had a couple of great great grandmothers who were Native Americans. Maybe that is what my mother meant when she said that ever woman should have a juicy past.