To the east of Lookout Mountain is Chattanooga Valley with the town at the head of it and the creek of that name flowing through, with Dry Creek as a branch emptying its waters into the Tennessee just south of the town.Beyond this to the east is Missionary Ridge, and parallel to it and just beyond is Chickamauga Valley, with the creek of that name running through it emptying into the river above Chattanooga, formed by East, Middle, and West Chickamauga Creeks, uniting with Pea Vine Creek between the latter two as a tributary.Chattanooga and West Chickamauga Creeks have a common source in McLemore's Cove, which is formed by Pigeon Mountain on the east, jutting to the north as a spur of Lookout Mountain, with the latter on the west, Missionary ridge running out as it enters this cove.The wagon road from Chattanooga to Rome, known as the La Fayette road, crosses Missionary Ridge into Chickamauga Valley at Rossville and proceeds thence nearly due south, crossing Chickamauga Creek at Lee and Gordon Mills, thence to the east of Pigeon Mountain, passing through La Fayette some twenty-two miles south of Chattanooga; it then continues on to Summerville, within twenty-five miles of Rome, and so on to the latter place.
Beyond these ranges is Taylor's ridge, with a number of lesser ranges between it and the Atlanta Railroad, running through Dalton.
Both Pigeon Mountain and Taylor's Ridge are very rough mountain ranges, with but few roads, and these only through gaps.At Dalton is the junction of the East Tennessee with the Atlanta Railroad, in the valley of the head waters of the Coosa River, which valley is here some ten miles wide and is the great natural passage-way into East Tennessee from the south.
To follow Bragg to Chattanooga and to cross the Tennessee above that place involved moving the army either to the north of the Sequatchie Valley by Dunlap or by Therman and Walling's Ridge, some sixty-five to seventy miles through a country poorly supplied with water, with no forage, and by narrow and difficult wagon roads.This route would take Rosecrans further away from his base of supplies and line of communication than that south of the river.It was over this northern route that Bragg anticipated the onward movement of the Army of the Cumberland.This would enable him to make a protracted defence of the town and retard the advance for weeks, if not months.But Rosecrans's plan of the campaign contemplated a much more hazardous movement and a far speedier one for the possession of Chattanooga.To accomplish this, however, it was necessary to cross the Cumberland Mountains with subsistence, ammunition, a limited supply of forage, and a bridge train; then to cross his army over the Tennessee River, after that over Sand or Raccoon Mountain into Lookout Valley, and from there to cross Lookout Mountain, and finally the lesser ranges--Missionary Ridge--if he went directly to Chattanooga, or to cross Missionary Ridge, Pigeon Mountain, and Taylor's Ridge, if he struck the railroad at Dalton or south of it.This involved the carrying by his army of ammunition for two great battles and twenty-five days' subsistence.
As soon as the repairs were made on the main line to Stevenson, Rosecrans ordered Sheridan's division to make an advance movement with two brigades to Bridgeport and one to Stevenson.Van Cleve had been ordered up with his divisions from Murfreesboro and was posted at McMinnville.On August 8th, stores being accumulated at the front, orders were issued to corps commanders to supply their troops, as soon as possible, with rations and forage sufficient for the general advance.
The movement over the Cumberland Mountains began on August 16th, and the troops were ordered to move as follows:
"Crittenden's corps in three columns to move through the Sequatchie Valley.Minty's cavalry to move on the left by Sparta, and after covering the left flank of Van Cleve to proceed to Pikesville.
"Thomas to move Reynolds and Brannan from University by way of Battle Creek, where they were to take post, concealed near its mouth.Negley and Baird to go by way of Tantallon and halt on Crow Creek between Anderson and Stevenson.
"McCook to move Johnson by Salem and Larkin's Ford to Bellefont.
Davis by Mount Top and Crow Creek to near Stevenson.The three brigades of cavalry by Fayetteville and Athens to cover the line of the Tennessee from Whitesburg up."These orders were complied with, and the movements completed by the evening of August 20th.Crittenden sent Hazen's brigade on a reconnoissance to Harrison's Landing, where he found the enemy throwing up works.On the next day Hazen took post at Poe's cross-roads.Wilder was sent to reconnoitre from Harrison's Landing to Chattanooga.On reaching Chattanooga, he was supported by Wagner's brigade, and both commands opened fire on the next day, shelling the town from across the river.This bombardment of the place caused it to be evacuated by the rebel troops, to points beyond range outside, and the withdrawal by Bragg of his stores to points of convenience on the railroad to the rear.Bragg then ordered Anderson's brigade to withdraw from Bridgeport.
The feint under Crittenden was so well timed that Bragg concentrated his immediate command at and above Chattanooga, leaving the crossing of the river by the main portion of our army later, unobstructed.
