Military Division of the Missouri

The Military Division of the Missouri was an administrative formation of the United States Army that functioned through the end of the American Civil War and the Indian Wars that continued after its conclusion. It was created by the War Department on February 3, 1865, at the direction of General Ulysses S. Grant to bring all the military departments west of the Mississippi River under a single commander.

Following the successful conclusion of the Mexican-American War, the administration of the United States Army was theoretically directed, under the President of the United States, by the Secretary of War and the general in chief. In practice the Secretary of War and the heads of the army's staff agencies—who reported directly to him (adjutant general, quartermaster general, commissary general, inspector general, paymaster general, surgeon general, chief engineer, colonel of topographical engineers, and colonel of ordnance)—exercised full authority, leaving the general-in-chief a figurehead. With a lack of central direction, policy and strategy were de facto developed by the commanders of the numbered geographical departments and three division headquarters. After October 31, 1853, the division echelon was eliminated and the six western departments consolidated into four (Departments of Texas, New Mexico, the West, and the Pacific), whose department commanders employed their troops as they saw fit. The system returned to six departments in 1858 when the Department of Utah was created in January, and the Department of the Pacific split into the Departments of California and Oregon in September.

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