(NOTE: This was prematurely published but I'll leave it here from now and revise and extend it as I originally planned when I can get to it).
I recently read The Earth Is Weeping; The Epic Story of the Indian Wars for the American West by Peter Cozzens, an account of the years from the Civil War to the final surrender of the Lakota Sioux in January 1891 after the fight at Wounded Knee. Over the past few years, I've also read The Apache Wars by Paul Hutton, The Heart of Everything That Is by Paul Drury and Tom Clavin (the story of Red Cloud, the only western Indian to defeat the US Army and obtain a favorable treaty), and Empire of the Summer Moon: Quanah Parker and the Rise and Fall of the Comanches by SC Gwynne, all of which are worth reading.
Each book is a sad tale of conflict, misunderstanding, betrayal, and broken promises. Beyond that it made me think about what were the realistic alternatives to what happened and the legacy that continues to this day as described by Naomi Schaefer Riley in her recent book, The New Trail of Tears: How Washington is Destroying American Indians.
Before returning to the Indians of the American West let's go all the way back to the initial European settlement of the Americas. The chances of the Indians of the Western Hemisphere meeting Europeans on grounds of equal strength were fatally compromised at the beginning, when they were exposed to illnesses for which they had no immunity. This unintended biological invasion diminished native populations between 70% and 90% across both continents within several decades of the first voyage of Columbus (for its impact on Mexico see Ten Years After: 1519-1529). In 1620 when the Pilgrims landed in Plymouth they found deserted Indian villages along the coast, with most of the population gone after an epidemic fueled by contact with Portugese and English fishermen who had trawled the area over the previous two decades.
Various Indian attempts to repel the invaders in the 16th and 17th centuries failed, often because of disunity and rivalries among the tribes (see Bloody Brook and The Sudbury Fight). One revolt was temporarily successful when the Pueblos drove Spanish settlers from New Mexico only to have their efforts reversed twelve years later (see Pueblo Revolt).
However, while Europeans cleverly manipulated tribal rivalries (Cortez' conquest of Mexico would have been impossible without the aid of tribes opposed to Aztec rule), Indians were capable of the same behavior. In North America this meant exploiting the rivalry of French and Britain, allowing Canada west of Quebec and American west of the Appalachians to avoid European settlement for a century. This strategy became doomed when France ceded its North American posessions to Britain when the French & Indian War ended in 1763. While the tribes tried a variant of this strategy during the American Revolution, continuing until the end of the War of 1812 during which time many allied themselves with the British, it proved unsuccessful as the English eventually withdrew from contesting the ambitions of the new American nation.