The 26th Missouri Infantry Regiment was organized from recruits across the state of Missouri, September through December 1861 and mustered in for three years service under the command of Colonel George Boardman Boomer.
The regiment was attached to the Department of the Missouri to February 1862.
2nd Brigade, 2nd Division, Army of the Mississippi, to April 1862.
1st Brigade, 3rd Division, Army of the Mississippi, to November 1862.
3rd Brigade, 7th Division, Left Wing, XIII Corps, Department of the Tennessee, to December 1862.
3rd Brigade, 2nd Division, XVII Corps, to December 1863.
These independent sharpshooters companies were used as dedicated skirmishing units and as snipers in static combat situations.
[1] Companies A, B, C, D, E, F, and G mustered out of service November 4, 1864, to January 9, 1865.
Grant's Central Mississippi Campaign November 1862 to January 1863.
Expedition to Yazoo Pass and operations against Fort Pemberton and Greenwood March 13-April 5.
Movement on Bruinsburg and turning Grand Gulf April 25–30.
Operations on Memphis & Charleston Railroad in Alabama October 20–29.
Tunnel Hill, Buzzard's Roost Gap and Rocky Faced Ridge February 23–25.
Railroad guard duty between Chattanooga and Allatoona, Ga., until November.
Cox's Bridge, Neuse River, N.C., March 19–20.