Final answer:
The Dakota Sioux uprising in 1862 was triggered by the U.S. government's failure to fulfill treaties, leading to starvation and land encroachment. The conflict resulted in the largest mass execution in U.S. history and the expulsion of the Sioux from Minnesota. Subsequent acts like the Indian Appropriations Act and the Dawes Act further stripped tribes of their sovereignty and propelled policies of assimilation.
Step-by-step explanation:
The Dakota Sioux uprising in 1862, also known as the Dakota War or the War of 1862, was primarily incited by the U.S. government's failure to make annuity payments promised to the Sioux, increasing hunger among their people, and the continuous encroachment on reservation lands. In a spontaneous act of rebellion, the Dakotas killed settlers who moved onto their tribal lands, resulting in a conflict where over one thousand White settlers were captured or killed, before the uprising was quelled by an armed militia. In the aftermath, President Lincoln commuted the death sentences of 265 out of 303 Sioux sentenced to death, but 38 Dakota men were hanged in the largest mass execution in U.S. history, and the survivors, along with their families, were expelled from Minnesota.
The Indian Appropriations Act of 1871 ended the recognition of Indian tribes as independent nations with which the U.S. would have to make treaties, simplifying the process for the U.S. government to acquire land. Later, the Dawes Act of 1887 aimed to force assimilation by dividing Native American reservation land into individual allotments and promoting individual property ownership among Native Americans. This policy reduced Native American communal and cultural cohesion, intended to dilute their collective power.
Over the years, the U.S. government's policies and actions continued to combat Native American sovereignty and remove tribes from their lands. Incidents like the Sand Creek Massacre further exemplified the brutality inflicted upon Native American tribes by settlers and militias. The federal government occasionally tried to reconcile, as seen in the Indian Reorganization Act and the Indian Self-Determination and Education Assistance Act, but conditions on reservations remained challenging. Nevertheless, these latter acts provided tribes the right to self-governance and assumption of control over some programs formerly managed by the Bureau of Indian Affairs (BIA).