...rom the north, he marched instead around the left flank of Bragg's army, boldly crossing the Cumberland Mountains, the Tennessee River, and two mountain ranges beyond. Bragg, seriously alarmed lest Rosecrans should 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 l...