The Knoxville Campaign was a series of American Civil War battles and maneuvers in East Tennessee during the fall of 1863 designed to secure control of the city of Knoxville and with it the railroad that linked the Confederacy east and west. Union forces under Maj. Gen. Ambrose Burnside occupied Knoxville, Tennessee, and Confederate forces under Lt. Gen. James Longstreet were detached from Gen. Braxton Bragg's Army of Tennessee at Chattanooga to prevent Burnside's reinforcement of the besieged Union forces there. Ultimately, Longstreet's own siege of Knoxville ended when Union Maj. Gen. William Tecumseh Sherman led elements of the Army of the Tennessee and other troops to Burnside's relief after Union troops had broken the Confederate siege of Chattanooga.