Why did general Rosecrans go to Chattanooga?

General William S. Rosecrans went to Chattanooga in the summer of 1863 to lead the Union Army of the Cumberland in an effort to secure a strategic victory in the Western Theater of the American Civil War. His objective was to capture Chattanooga, a vital transportation hub, and to counter the Confederate forces led by General Braxton Bragg. The Union's successful control of Chattanooga would open the door to further military operations in the South, particularly against Atlanta and beyond.