In late June of 1863, Union Major General William S. Rosecrans launched a massive offensive from Murfreesboro to drive Confederate General Braxton Bragg's 43,000-man Army of Tennessee from its entrenchments at Shelbyville and Wartrace, possibly out of the state, capture Chattanooga, and rescue loyal East Tennessee from rebel control. The campaign was bold and swift, with relatively few engagements. Rosecrans divided his army into four independent columns to maneuver Bragg out of his Shelbyville trenches: Major General Gordon Granger advanced south from Murfreesboro toward Shelbyville, Major General Alexander McCook moved south through Liberty Gap, Major General George Thomas marched southeast down the Manchester Pike toward Chattanooga, and Major General Thomas L. Crittenden advanced east along the McMinnville Turnpike before turning south to cross the Highland Rim below Bradyville at Gillie’s Gap. Rosecrans intended to concentrate most of his army at Manchester and then push on to Tullahoma, forcing Bragg either to retreat or to fight on ground of Rosecrans's choosing. Despite rain and poor roads, the Union advance moved forward, and by the evening of June 27 the Union held Shelbyville and Manchester. Bragg's army narrowly escaped to take up positions around Tullahoma. By July 4th, the 70,000-strong Union Army of the Cumberland had forced a Confederate retreat to Chattanooga, leaving nearly all of Tennessee in Union hands.