Final answer:
Despite previous victories, Native American tribes including Red Cloud's Lakota were coerced onto reservations due to U.S. expansion, military pressure, and unfulfilled treaty obligations by the U.S. government. The internal divisions and external conflicts led to a depletion of resources and options, forcing Native Americans to accept the reservation system as a means of survival.
Step-by-step explanation:
Native American Surrender and Reservations
On November 6, 1868, Red Cloud and his allies signed a treaty with the American government, despite Native American success in battles. The harsh realities following America's westward expansion, conflicts, and policies forced Native Americans into a position of surrender. The U.S. Army's increase in numbers post-battle, the extermination of encampments, and the forceful pushing of Native Americans to reservations exhausted any opportunities to maintain sovereignty. Many treaties failed to be honored by the United States, having promised goods, rights, and monies in exchange for vast tracts of land only to leave those agreements unfulfilled.
Additionally, divisions within Native American tribes and differing perspectives on past alliances, such as those with the Confederacy during the Civil War, led to further conflicts and diminished any possibility of a unified resistance. Even the leaders like Sitting Bull who fled or worked towards indigenous perspectives eventually succumbed to the overwhelming pressure exerted by the U.S. government and the continuous military campaigns against their people. Ultimately, many tribes were coerced into surrendering by threat of force, loss of a land base, or lack of resources - a stark contrast to earlier successes such as at Little Bighorn.