After an earlier defeat at Chickamauga in Georgia, the Union forces, under Grant's defeat, withdrew across the state boundary to Chattanooga, Tennessee in 1863. The Confederates, under Braxton Braggs, set down a blockade and cut off all Union supply goods and communications. On Lookout Mountain, three miles southwest of Chattanooga and on parts of Missionary Ridge, Bragg's army was there and ready to go!.
The Union army took over Brown's Ferry on the Tennessee River, west of Chattanooga, by trying to get back the supply line on October 27 and 28.
The army of X1 and X11 Corps under General Joseph Hooker tried to take over the valley of Lookout Creek, west of Lookout Mountain, and succeeded. General Grant then stopped all movement and operations until General Sherman graced them with his presence. .
The major part of the battle occurred when Sherman's forces, made up of six divisions, bombarded the Confederates on the northern slopes of Missionary Ridge. Unable to stop it, Grant commanded George Thomas to make an assault on the Confederat Hooker's forces stormed the southern and eastern flanks of Missionary Ridge.
Thomas's army, totally disregarding the commands to march no farther than the first lines of earthworks, kept going up the slopes. In this action one of the most incredible changes in military history occurred. The troops carried the enemies" fortifications along the Crest. This incidence alarmed the Confederate troops, and they fled in chaos, like little rats scurrying in fear. .
That night Bragg's army withdrew northward. Grant's win forced the Confederates flee to Tennessee and made Sherman's march through Georgia possible. The Union's casualties were about 5,800, and the Confederate's casualties were about 6,700. Although it was an arduous battle, Grant won and the north was granted an awesome victory, which made up for the loss at Chickamauga. .