... seize the railroad communications behind him, hastily evacuated Chattanooga, but not with the intention of flight, as Rosecrans erroneously believed and reported. When, on September 9, the left of Rosecrans 's army marched into Chattanooga without firing a shot, the Union detachments were so widely scattered in separating mountain valleys, in pursuit of Bragg's imaginary retreat, that Bragg believed he s...