Joseph T. Derry , A. M. , Author of School History of the United States; Story of the Confederate War, etc., Confederate Military History, a library of Confederate States Military History: Volume 6, Georgia
Clement Anselm Evans, Ed.

On the 16th of August, Rosecrans put his army in motion to pass the Cumberland mountains and marched southward. Having crossed the Tennessee river in the vicinity of Stevenson and Bridgeport, Ala., the Federals found themselves confronted by Sand mountain, the northern extremity of which is known as Raccoon mountain. At the eastern base of this ridge runs Lookout creek, separating from Sand mountain the parallel ridge known as Lookout mountain, whose abrupt termination, where Lookout creek empties into the Tennessee, looms up in the sky just southwest of Chattanooga. Beyond Lookout mountain a valley runs in the same general direction, drained by Chattanooga creek, east of which is another parallel ridge, more passable, called Missionary ridge, the northward termination of which is east of Chattanooga and is pierced by the tunnel of the Georgia State railroad. East of Missionary ridge lies the most important of these valleys, McLemore's cove, which is traversed by the west branch of Chickamauga creek, and ends 25 miles below Chattanooga in a junction of the mountain ridges. Pigeon mountain is the next running a parallel course of 40 miles, and still further east are the ranges of Chickamauga hills and Taylor's ridge. These must all be traversed by Rosecrans, six ridges separated by valleys and creeks, before he could reach the railroad communications of Bragg.

On September 8th, Rosecrans, having determined to flank his opponent out of Chattanooga, ordered an advance on the right and center of his 45-mile line, up to this time hid behind the Lookout range. General Bragg perceiving these movements evacuated Chattanooga after he had telegraphed the president, ‘Rosecrans' main force attained my left and rear. I followed and endeavored to bring him to action and secure my ’