William T. Sherman brought four battle-hardened divisions from Mississippi, arriving on November 15, 1863. Grant immediately showed more confidence and heartiness: he and Sherman were like a team in harness. Joseph Hooker had already brought four divisions of the Army of the Potomac, and Grant now enjoyed numerical superiority. Not only had the Union done a better job of coordinating its forces, but the Confederates made a serious, perhaps fatal, mistake of dividing theirs. Because of the animosity that existed between him and General Longstreet, Bragg sent Longstreet and almost ten thousand men away to attack General Burnside’s garrison at Knoxville. Grant did not know all of this, of course, but if he had enjoyed a bird’s-eye view, he would have been delighted to see his foe divide his forces at the very time when his were being concentrated.