Prior to the outbreak of the American Civil War, the US and the Native tribes of the Southwest had a tumultuous relationship. Thousands of people from the eastern US had begun pouring into the Southwest and into ancestral tribal lands in increasing numbers every year after Mexico ceded to the US the territories that made up the American Southwest following the conclusion of the Mexican-American War in 1848. Eventually, tensions reached a tipping point. The Apache, Comanche, Kiowa, Navajo, and other tribes began retaliating by attacking forts, army patrols, towns, and wagon trains on their land after enduring years of the killing and enslavement of their people, theft of their livestock and game, and colonizers illegally encroaching on their land. This conflict initially consisted of small ambushes, quick raids, and other elements of guerilla warfare, but grew in size, scale, and regularity following the outbreak of the American Civil War.
This conflict was a bitter one, as the Union and Confederate armies used scorched earth tactics on Native communities, as well as on each other.
In the midst of this devastation, the Union Army began forcibly relocating the Native tribes of the Southwest onto barren, desolate reservations.