The army saw little action the rest of 1862 and Butler was replaced by Major General Nathaniel P. Banks on December 17. Banks assumed command of the Department of the Gulf and the Army of the Gulf. At the time the Army of the Gulf consisted of only one corps, the XIX Corps, which Banks was also appointed command of. Banks led the army in several engagements in lower Louisiana that eventually led to the Siege of Port Hudson, this army's first major engagement. The army endured the siege and the post was finally surrendered by Confederate forces on July 9, 1863. The next year the XIII Corps and two divisions of the XVI Corps were added to the department, increasing the army to over three corps. Banks retained command of the army and department while Gen. William H. Emory assumed command of the XIX Corps.