Trans-Mississippi Department applies to jurisdiction Indian Territory
The Trans-Mississippi Department was a geographical subdivision of the Confederate States Army comprising Arkansas, Missouri, Texas, western Louisiana, Arizona Territory and the Indian Territory; i.e. all of the Confederacy west of the Mississippi River. It was the last military department to surrender to United States forces in 1865.History
The Trans-Mississippi Department was established on May 26, 1862, at Little Rock, Arkansas. It absorbed the previously established Trans-Mississippi District (Department Number Two) which had been organized on January 10, 1862, to include the Indian Territory, Missouri, Arkansas (except for the country east of St. Francis County, Arkansas, to Scott County), Missouri, and that part of Louisiana north of the Red river. The Trans-Mississippi Department had its headquarters at Shreveport, Louisiana, and Houston, Texas. It was responsible for the Confederate theater of operations west of the Mississippi. Its forces were sometimes referred to as "Army of the Southwest" and, as a result of being largely cut off from the Confederate government in Richmond late in the War, became popularly known as "Kirby-Smithdom".