The protection of the Great Plains fell under the 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 Scott Hancock was assigned to the department in 1866 but had mishandled his campaign, resulting in Sioux and Cheyenne raids that attacked mail coaches, burned the stations, and killed the employees. They also killed and kidnapped a considerable number of settlers on the frontier. Under pressure from the governors, General Grant turned to Sheridan. In September 1866, Sheridan arrived at the former Fort Martin Scott near Fredericksburg, Texas, where he spent three months subduing Indians in the Texas Hill Country.