Here are historians Craig Symonds and John Marszalek talking about the 1863 Chattanooga Campaign in a program sponsored by the New York Historical Society and hosted by author Harold Holzer. The two historians do a wonderful job, but unfortunately they retain, I believe, a discredited view of Braxton Bragg.
The video’s description reads, “Historians talked about the Civil War’s Chattanooga Campaign, which took place in the fall of 1863 and resulted in Union forces under General Ulysses S. Grant breaking through a Confederate siege. The panelists spoke how General Grant and his top lieutenants outmaneuvered the Confederate leadership to rout the southern troops and force them into northern Georgia. The Union victory opened the door for General William Tecumseh Sherman’s Atlanta Campaign the following year.”