Hooker's military career was not ended by his poor performance in the summer of 1863. He went on to regain a reputation as a solid corps commander when he was transferred with the XI and XII Corps of the Army of the Potomac westward to reinforce the Army of the Cumberland around Chattanooga, Tennessee. Hooker was in command at the Battle of Lookout Mountain, playing an important role in Lt. Gen. Ulysses S. Grant's decisive victory at the Battle of Chattanooga. He was brevetted to major general in the regular army for his success at Chattanooga, but he was disappointed to find that Grant's official report of the battle credited his friend William Tecumseh Sherman's contribution over Hooker's.