Question: what was the last major battle of the plains indian wars

title: American Indian Wars
text: After the Civil War , all of the Indians were assigned to reservations ; the role of the army was to keep them there . The reservations themselves were under the control of the Interior Department . Control of the Great Plains fell under the Army 's Department of the Missouri , an administrative area of over 1,000,000 mi. 2 , encompassing all land between the Mississippi River and the Rocky Mountains . Maj. Gen. Winfield S. Hancock had led the department in 1866 , but had mishandled his campaign , resulting in Sioux and Cheyenne raids that attacked mail stagecoaches , burnt the stations , and killed the employees . They also raped , killed , and kidnapped many settlers on the frontier . Under pressure from the governors , Commanding General Ulysses Grant turned to Philip Sheridan . In September 1866 , Sheridan went to Fort Martin Scott in Texas , taking three months to stop Indian raids . During his lifetime Sheridan was known as a fierce enemy of the Indians , and his approach to the Indians was encapsulated when he is thought to have said `` The only good Indian is a dead Indian '' , although he himself denied having said this when criticized by his political opponents .