Union Military Organisations: Gulf Coast Theatre
Go to Western Territories and Pacific Coast Theatre / Pacific Coast Theatre / Trans-Mississippi, Northwest, and Frontier Theatres / Western Theatre / Eastern Theatre / Capital and North-Eastern Theatre / Atlantic Coast Theatre for detailed summaries.
This theatre broadly covers the states of Texas, Louisiana, Alabama, Florida, and adjacent operational regions.
The outbreak of war found only isolated outposts still in the hands of the Federal authorities and all but one of these were quickly taken over by the Confederates with varying degrees of resistance. The important Department of Texas continued in nominal existence until November 1862 despite there being no organised military force in the state since April 1861.
The exception was Fort Pickens near Pensacola, Florida. And a new Department of Florida was established almost immediately after the outbreak of hostilities with headquarters at Fort Pickens. Theoretically, the Department was responsible for the entire state of Florida although the fort was the only Union-occupied ground. By 11 January 1862, sufficient progress had been made to establish the Department of Key West to oversee the western Florida coast and islands.
The Department of the South was established in March 1862 and took control of the Department of Florida and the Department of Key West, each of which was reduced to a District of that Department. Responsibility for western Florida and the coastal section of Alabama alternated between the Department of the Gulf and the Department of the South, depending on the evolving military situation and progress of operations.
The seizure of New Orleans in early 1862 led to the capture of much of Louisiana and enabled Union warships to penetrate inland up the Mississippi and Red Rivers, assisting the army as it gradually took control of the lower Mississippi by July 1863. The Department of the Gulf was established under B F Butler in February 1862, to direct the operations in Louisiana. The coast of Texas was added officially in November 1862, coinciding with the appointment of N P Banks to replace B F Butler. As new territory was captured, Districts were set up to direct local operations. The Department of the Gulf was the primary authority for operations in the theatre until the end of the war, and its main field force was known as the Army of the Gulf. The bulk of the army was transported from the North by the Navy, but they were increasingly supplemented by detachments coming southwards along the Mississippi and forces recruited locally from freed slaves.
In May 1864 the failed advance towards Texas from the north (Arkansas) and east (Louisiana) proved the need for strategic coordination of operations west of the Mississippi. As a result, the Military Division of West Mississippi (Trans-Mississippi Military Division) was created, responsible for the Department of the Gulf, the Department of Arkansas, and the Department of the Missouri. By the end of 1864 attention was being directed east of the Mississippi and the Department of the Mississippi was added to the Military Division in November 1864. In January 1865, as the objective switched more intensively towards Mobile Bay and the Alabama Coast, the Department of the Missouri (January 1865) was detached, to be followed by the Department of Arkansas in March 1865. After combining all available field forces in a new Army of West Mississippi in February 1865, the campaign was begun against Mobile. The Districts around Mobile were transferred temporarily from their Departments to the direct control of the Military Division for the same operational reasons.
In May 1865 the purpose of the Military Division was complete, and it was discontinued. The Department of the Gulf operated independently from May 1865, however, it passed control over Louisiana and Texas to the new Military Division of the Southwest as a show of strength was presented to the French authorities in Mexico. The Department retained its authority in Mississippi, and coastal parts of Alabama and Florida until the post-war reorganisation of 27 June 1865, when it ceased to exist.
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 Gulf
Military Division of the Southwest
Military Division of West Mississippi
Department of Florida #1
Department of Florida #2
Department of the Gulf
Department of Key West, Florida
Department of Louisiana
Department of Texas #1
Department of Texas #2
District of Alabama
District of South Alabama
District of Baton Rouge, Louisiana #1
District of Baton Rouge, Louisiana #2
District of Baton Rouge and Port Hudson, Louisiana
District of Bonnet Carré, Louisiana
District of Carrollton, Louisiana
District of Florida
District of West Florida #1
District of West Florida #2
District of West Florida and South Alabama
District of Key West and Tortugas
District of La Fourche, Louisiana
District of East Louisiana
Eastern District of Louisiana
District of Northeast Louisiana
Northern District of Louisiana
Southern District of Louisiana
Western District of Louisiana
District of Morganza, Louisiana
Defences of New Orleans, Louisiana
District of Pensacola, Florida
District of Port Hudson, Louisiana #1
District of Port Hudson, Louisiana #2
Central District of Texas
Eastern District of Texas
Western District of Texas
Sub-District of Baton Rouge, Louisiana
Sub-District of West Florida
Sub-District of Mobile, Alabama
Sub-District of Port Hudson, Louisiana
Army of the Gulf
Army of West Mississippi
XIII Corps Gulf #1
III Corps Gulf #2
XVI Corps Gulf
XIX Corps Gulf
XXV Corps Southwest
Reserve Corps Gulf