By mid-December 1861 Sherman had recovered sufficiently to return to service under Halleck in the Department of the Missouri. In March, Halleck's command was redesignated the Department of the Mississippi and enlarged to unify command in the West. Sherman's initial assignments were rear-echelon commands, first of an instructional barracks near St. Louis and then in command of the District of Cairo. Operating from Paducah, Kentucky, he provided logistical support for the operations of Brig. Gen. Ulysses S. Grant to capture Fort Donelson in February of 1862. Grant, the previous commander of the District of Cairo, had just won a major victory at Fort Henry and been given command of the ill-defined District of West Tennessee. Although Sherman was technically the senior officer, he wrote to Grant, "I feel anxious about you as I know the great facilities [the Confederates] have of concentration by means of the River and R Road, but [I] have faith in you—Command me in any way."