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.
Friction between the Secretaries of War and the generals in chief, and particularly between Jefferson Davis and Winfield Scott, obstructed reforms in the staff system that might have brought unity of command and civilian control of the military.
[2] The new department included Missouri, Arkansas, Illinois, Kentucky west of the Cumberland River and at times, Kansas.
It briefly merged with the Department of Mississippi in 1862, but was recreated September 19, now consisting of Missouri, Arkansas, Kansas, and the Indian Territory.
Curtis created a new district, the Upper Arkansas, to wage the war but he was wholly incapable of locating his opponents.
Pope took command of the Division of the Missouri on February 3, 1865, at Fort Leavenworth, Kansas, with headquarters moving soon after to St. Louis.
However, the Division of the Missouri still included all states and territories west of the Mississippi River, north of Texas, and east of Idaho, Nevada, and Arizona.
On July 28, 1866, Congress enacted the peacetime establishment of the United States Army and Sherman was promoted to lieutenant general.
Philip H. Sheridan was promoted to lieutenant general and assigned to command the Division of the Missouri with headquarters at Chicago.