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, and possibly out of Tennessee. Rosecrans aimed to capture Chattanooga and to “rescue loyal East Tennessee from the hands of the rebels.” Dividing his army into four independent columns, he advanced south toward Shelbyville, through Liberty Gap, southeast along the Manchester Pike toward Chattanooga, and east along the McMinnville Turnpike before turning south across the Highland Rim at Gillie’s Gap. By June 28, the bulk of the Union army was in Manchester, and Union forces also held Shelbyville and Bragg’s entrenched lines. Despite rain and poor roads, Rosecrans pressed on toward Tullahoma. Bragg crossed the Elk River at Allisonia on June 30 and began a general retreat, briefly establishing headquarters at Dechard before moving onto the Cumberland Plateau with Joe Wheeler’s cavalry covering the rear. By July 4, Rosecrans had forced the Confederates back to Chattanooga, leaving nearly all of Tennessee in Union hands, and made Winchester his headquarters.