Union Military Organisations: Western Theatre

Union Military Organisations: Western Theatre

Go to Western Territories and Pacific Coast Theatre / Pacific Coast Theatre / Trans-Mississippi, Northwest, and Frontier Theatres / Gulf Coast Theatre / Eastern Theatre / Capital and North-Eastern Theatre / Atlantic Coast Theatre for detailed summaries.

This theatre broadly covers the states of Illinois, Indiana, Ohio, Kentucky, Tennessee, Mississippi and adjacent operational regions in Alabama, Georgia, South Carolina, and North Carolina.
This was the decisive theatre of operations where the foundations of Union victory were established. Being geographically central, operations in this theatre inevitably impinged on and overlapped with all the other theatres of war. The military organisation therefore experienced a complex evolution as attention was frequently diverted to diverging and tangential operations. Nevertheless, the main focus remained on two main lines of advance by the Union Army, both assisted by naval forces on the inland rivers. The first followed the line of the Mississippi southwards and the second, followed the line of the Tennessee River into northern Georgia during 1862 to 1864. Exploitation of the latter advance in late 1864 and 1865 took dominant Union forces from the western theatre across Georgia to the Atlantic Coast and then north through the Carolinas.
The first attempt to bring these extensive operations under a unified command was comparatively short-lived. The Department of the Mississippi was created in March 1862 to command operations in states bordering the Mississippi, Tennessee, Cumberland, and Ohio Rivers. The occupation of Missouri, Kentucky, and Western Tennessee was largely accomplished, although those areas remained under continual threat of raids and reconquest. This supreme command was dissolved into its constituent departments in September and October 1862 as the objectives of each region once again diverged.
A unified command structure was more fully achieved in October 1863 with the creation of the Military Division of the Mississippi. This development became possible after control of the Mississippi River was achieved during the summer and attention concentrated on the line of invasion along the Tennessee River and into Georgia, with operations in eastern Tennessee subordinated to it. The inexorable progress of the armies of the Military Division through Georgia in 1864, and into the Carolinas in 1865 during brought those regions, and their Departmental commands in the Atlantic Coast Theatre, within its sphere of operational control but not necessarily its administrative control.

This is an alphabetical Index of each Organisation by Level and then by name 

Details of each specific organisation can be found in the Introduction to Union Military Organisations – Types -by searching for the Level and then the Name of the Organisation

Military Division of the Mississippi
Military Division of the Tennesse

Department of Alabama
Department of the Cumberland #1
Department of the Cumberland #2
Department of Kentucky #1
Department of Kentucky #2
Department of Mississippi
Department of the Mississippi #1
Department of the Mississippi #2
Northern Department
Department of the Ohio #1
Department of the Ohio #2
Department of the Ohio #3
Department of Tennessee
Department of the Tennessee

District of Northern Alabama
District of Cairo, Illinois #1

District of Cairo, Illinois #2
District of Cairo, Illinois #3
District of the Clinch, Tennessee
District of Columbus
District of Corinth, Mississippi
District of Illinois #1
District of Illinois #2
District of Indiana #1
District of Indiana #2
District of Indiana #3
District of Indiana and Michigan
District of Jackson, Tennessee
District of Kentucky
District of Central Kentucky
District of Eastern Kentucky
District of Western Kentucky #1
District of Western Kentucky #2
District of Western Kentucky #3
District of Louisville, Kentucky
District of Memphis, Tennessee
District of Michigan
District of Mississippi
Northern District of Mississippi
Southern District of Mississippi
Western District of Mississippi
District of Nashville, Tennessee
District of Natchez, Mississippi
District of Ohio
District of the Ohio
District of Tennessee
District of East Tennessee
District of Middle Tennessee #1
District of Middle Tennessee #2
District of West Tennessee #1
District of West Tennessee #2
District of Vicksburg, Mississippi

Sub-District of Columbus, Tennessee
Sub-District of Jackson, Tennessee
Sub-District of North Central Kentucky
Sub-District of South Central Kentucky
Sub-District of Eastern Kentucky
Sub-District of Memphis, Tennessee
Sub-District of Somerset, Kentucky

Army of the Cumberland
Army of Georgia
Army of Kentucky #1
Army of Kentucky #2
Army of the Mississippi #1
Army of the Mississippi #2
Army of the Ohio #1
Army of the Ohio #2
Army of the Tennessee
Army of West Tennessee

Hooker’s Command Cumberland

I Corps Cumberland
I Corps Mississippi
I Corps Ohio
II Corps Cumberland
II Corps Mississippi
II Corps Ohio
III Corps Cumberland
III Corps Ohio
IV Corps Cumberland
IX Corps Ohio #1
IX Corps Ohio #2
IX Corps Tennessee
XI Corps Cumberland (Hooker’s Command)
XII Corps Cumberland (Hooker’s Command
XIII Corps Tennessee #1
XIII Corps Tennessee #2
Centre XIII Corps Tennessee
Left Wing XIII Corps Tennessee
Right Wing XIII Corps Tennessee
XIV Corps Cumberland
XIV Corps Georgia
XIV Corps Mississippi
Centre XIV Corps Cumberland
Left Wing XIV Corps Cumberland
Right Wing XIV Corps Cumberland
XV Corps Tennessee #1
XV Corps Tennessee #2
XVI Corps Tennessee
Detachment Army of the Tennessee (XVI Corps)
Left Wing XVI Corps Tennessee
Right Wing XVI Corps Tennessee
XVII Corps Tennessee
XX Corps Cumberland #1
XX Corps Cumberland #2
XX Corps Georgia
XXI Corps Cumberland
XXIII Corps Ohio
Cavalry Corps Cumberland
Cavalry Corps Mississippi
Cavalry Corps Ohio
Reserve Corps Cumberland