reported the movement of the rebel forces from East Tennessee and their concentration at Chattanooga. To dislodge him from that place it was necessary to carry Lookout Mountain, or so to move as to compel him to quit his position by endangering his line of communication. The latter plan was chosen.
The cavalry was ordered to advance on our extreme right to Summerville, in Broomtown Valley, and General McCook was ordered to support the movement by a division of infantry thrown forward to the vicinity of Alpine, which was executed on the 8th and 9th of September.
General Thomas was ordered to cross his corps by Frick's or Cooper's and Stevens' Gaps and occupy the head of McLemore's Cove.
General Crittenden was ordered to reconnoiter the front of Lookout Mountain, sending a brigade up an almost impracticable path called the Nickajack trace to Summertown, a hamlet on the summit of the mountain overlooking Chattanooga, and holding the main body of his crops either to support these reconnaissances to prevent a sortie of the enemy over the nose of Lookout, or to enter Chattanooga in case the enemy should evacuate it or make but feeble resistance. Simultaneously with this movement, the cavalry was ordered to push by way of Alpine and Broomtown Valley and strike the enemy's railroad communication between Resaca bridge and Dalton.
These movements were promptly begun on the 8th and 9th of September. The reconnaissance of General Crittenden on the 9th developed the fact that the enemy had evacuated Chattanooga the day and night previous and his advance took peaceable possession at 1 p.m.
His whole corps, with its trains, passed around the point of Lookout Mountain on the 10th and encamped for the night at Rossville, 5 miles south of Chattanooga.
During these operations, General Thomas pushed his corps over the mountains at the designated points, each division consuming two days in the passage.
The weight of evidence, gathered from all sources, was that Bragg was moving on Rome, and that his movement began on the 6th of September. General Crittenden was therefore directed to hold Chattanooga, with one brigade, calling all the forces on the north side of the Tennessee across, and to follow the enemy's retreat vigorously, anticipating that the main body had retired by Ringgold and Dalton.
Additional information, obtained during the afternoon and the evening of the 10th of September, rendered it certain that his main body had retired by the La Fayette road, but uncertain whether he had gone far. General Crittenden was ordered, at 1 a.m. on the 11th, to proceed to the front and report, directing his command to advance only as far as Ringgold, and order a reconnaissance to Gordon's Mills. His report, and further evidence, satisfied me that the main body of the rebel army was in the vicinity of La Fayette.
General Crittenden was therefore ordered to move his corps, with all possible dispatch, from Ringgold to Gordon's Mills, and communicate with General Thomas, who had by that time reached the eastern foot of Lookout Mountain. General Crittenden occupied Ringgold during the 11th, pushing Wilder's mounted infantry as far as Tunnel Hill, skirmishing heavily with the enemy's cavalry. Hazen