The department was constituted on February 23, 1862, when theUnited States War Department issued General Orders No. 20; the department consisted of "...all of the coast of the Gulf of Mexico west of Pensacola harbor, and so much of the Gulf States as may be occupied by the forces underMajor GeneralB.F. Butler." On March 20, 1862, Butler activated his command atShip Island,Mississippi by issuing General Orders No. 1 (Department of the Gulf) assuming his new command.[1]
United States Navy'sWest Gulf Blockading Squadron capturedNew Orleans,Louisiana on April 29, 1862, Butler moved his headquarters to New Orleans on 1 May. The department, sometimes referred to as the Army of the Gulf, became a union occupying force in the region.[1]
The department, frequently referred to as the Gulf District, was established on July 2, 1862, as a part of Department No. 2; its area was defined as the coast from the Pearl River to the Apalachicola River northward to latitude 32° north. On November 3, 1862,[3] the northern boundary was extended to latitude 33° north. On July 25, 1863, the department/district was transferred to the Department of Mississippi and Eastern Louisiana.[4] It remained in that department only until January 28, 1864, when it was transferred to the Department of Alabama and Eastern Mississippi.[4] Upon being transferred, the department/district boundaries were redefined as beginning at the mouth of the Pearl River, running north to latitude 32° north, east to theGeorgia State line and south to theGulf of Mexico.[4] On May 8, 1864, the boundary was again modified to define the eastern edge as being the intersection of latitude 32° north with a line running from the junction of the Coosa and Tallapoosa to point where the Choctawhatchee River entered Florida then following the Choctawhatchee to its mouth on the Gulf of Mexico.[4] The department/district surrendered on May 4, 1865.[4]
The department was constituted by General Order 7, Headquarters of the Army, Adjutant General's Office, dated March 11, 1898. The order specified that the department was to include the states ofSouth Carolina,Georgia,Florida,Alabama,Mississippi,Louisiana andTexas. All of the named states had previously been included in theDepartment of the East except Texas which had been the sole state in theDepartment of Texas. The depart was redesignated as the Department of the South on March 12, 1898, and back to the Department of the Gulf on March 18, 1898.Brigadier GeneralWilliam M. Graham assumed command of the department on March 14, 1898. The department was headquartered inAtlanta, Georgia.[6]
On October 25, 1899, the department was merged with the Department of the East.[7] It was reestablished in December 1903.[8]
