During the month of September and into early October, the Army of the Cumberland was reinforced by the troops of Army of the Tennessee, commanded by Maj. Gen. William Tecumseh Sherman, along with two corps from the Army of the Potomac under Maj. Gen. Joseph Hooker. Ulysses S. Grant, now in overall command of Union forces in the west under the newly created Military Division of the Mississippi, replaced Rosecrans in command with George H. Thomas; Grant had command of the combined Union forces. During the early morning hours of October 27, Union forces captured Brown's Ferry, which opened a supply route to Alabama; A Confederate counterattack at Wauhatchie during the night of October 28–29 tried to recapture the ferry but failed. Bragg then on November 5 sent Longstreet's corps to Knoxville and nearly all of his cavalry away, reducing his army's strength; Bragg hoped that Grant would be forced to detach part of his own force to relieve the Union garrison at the city. The final Union attack on the Confederate army started November 24, when Hooker captured Lookout Mountain and threatened the Confederate left flank. The next day, Sherman attacked the Confederate right flank on Missionary Ridge but was stalemated. To help Sherman and to draw Confederate units from the right, Grant ordered a demonstration against the Confederate center. This demonstration by Thomas turned into a full-fledged attack which broke through the Confederate line. Bragg retreated back into north Georgia, regrouping around Dalton. His request to be relieved was accepted on December 1. Hardee temporarily took command of the army, but refused an offer or permanent command. Instead Davis appointed Joseph Johnston to command the army in December 1863.