Between the first Fort Laramie treaty of 1851 and the massacre at Wounded Knee in 1890, the United States converted the Great Plains from Native territory into reservations and then into settler property. Treaties assigned bounded territories and then reduced them; the 1868 Fort Laramie treaty guaranteed the Black Hills to the Oceti Sakowin, and the guarantee was broken after the gold rush of 1874. Military campaigns, the near-extermination of the bison herds on which Plains subsistence depended, and the withholding of rations enforced confinement. The Dawes General Allotment Act of 8 February 1887 then divided reservations into individual holdings of 80 to 160 acres and opened the remainder to sale: Britannica records that about two-thirds of the 138 million acres held in 1887 had been lost by 1932. Britannica dates the Plains Wars from the early 1850s to the late 1870s and the reservation and allotment regime carried the process into the twentieth century.
The United States confined the Native nations of the Great Plains to reservations by treaty and war, destroyed the bison herds, and then broke up the reservations under the Dawes Act
There was no census of the Plains nations; the figure rests on Indian Office agency estimates and later reconstructions, which put the Plains tribes at roughly 100,000-250,000 in the mid-nineteenth century, with the Lakota, Cheyenne, Arapaho, Comanche, Kiowa, Crow, Blackfeet and the village peoples of the Missouri making up most of it. Smallpox and cholera epidemics of 1837 and 1849 had already cut the village nations severely.
No defensible aggregate death toll exists for four decades of intermittent campaigning across the Plains. Army returns record United States military casualties reasonably well and Native casualties badly; deaths from starvation and disease on the reservations after the bison collapse were not counted at all. The best-documented episodes - the Sand Creek and Wounded Knee massacres - are given separately, and adding them to unrecorded campaign and reservation mortality would produce a false precision.
Britannica's accounts of the Plains Wars and the Fort Laramie treaties describe winter attacks on villages with the destruction of lodges, food stores and horse herds, and the use of ration control and the collapse of the bison herds to compel and maintain confinement on reservations.
United States of America