Sheridan’s division of the Twentieth Corps was pushed forward to Stevenson and Bridgeport. The commissary and quartermaster-stores were accumulated at Stevenson as rapidly as possible. By the 8th of August these supplies were sufficient in quantity to justify a distribution of them to the different commands, preparatory to an advance across the river and over the difficult ridges, that lay at almost right angles to the line of movement. The advance of the main army began August 16.
The Fourteenth Corps crossed along the railroad line, or near to it. Its advance was soon at Stevenson and some of it at Bridgeport. The Twenty-first Corps—which formed the left of the army at McMinnville—crossed by the way of Pelham, a small village on the plateau, to Thurman’s in the Sequatchie Valley. Minty’s cavalry covered the left flank by way of Pikeville, a village at the head of Sequatchie Valley. The Twentieth Corps also came to Stevenson and its vicinity, but by another route—to the right—than that taken by the Fourteenth, namely, via Bellefont, ten miles southwest of Stevenson, and Caperton’s Ferry, which is the river point nearest to Stevenson.
All these crossings of the plateau were made without resistance by the enemy, although there were small Confederate cavalry outlooks here and there, which fell back when the Union troops appeared. It seemed as if Bragg desired to have the Union Army advance as far as possible from its base of supplies into the mountain gorges and over a long and difficult line of communications. That course would afford him a better chance, as his army being reinforced would be in better condition to successfully attack and destroy the Union Army.
In order to save the hauling of full forage for the animals, General Rosecrans had delayed his movement until the corn should be sufficiently ripe. No detail seemed wanting in the preparations for the difficult campaign. Enough ammunition was provided for at least two battles, and twenty-five days rations for the troops were hauled in wagons.
The Tennessee River had to be crossed by the different corps; in order to conceal this movement and deceive the enemy at Chattanooga, Hagen’s brigade of Palmer’s division, and Wagner’s of Wood’s of the Twenty-first Corps, accompanied by Wilder’s mounted infantry of Reynolds’s division, crossed Walden’s Ridge from the Sequatchie Valley into the valley of the Tennessee. These troops made ostentatious demonstrations upon Chattanooga from the north side of the river. Wilder—with four guns of Lilly’s battery—appeared suddenly before Chattanooga, threw some shells into the city, sunk the steamer “Paint Rock,” lying at the city landing, then ascending the river, feigned to examine the crossings, making frequent inquiry as to their difficulty and the character of the country. On the other side of the river east of Chattanooga, General Cleburne was sent by Bragg to make preparations for defending the crossings against the supposed advance of Rosecrans’s army. He fortified the ferry crossings. General Buckner—who commanded in East Tennessee against the forces of Burnside—expressed as his opinion on August 21, that General Rosecrans would cross above the mouth of Hiawassie River—a stream flowing northwards—and transfer his forces into Tennessee on its south bank, some thirty-five miles northeast of Chattanooga. Buckner’s army was at the point mentioned.
Rosecrans’s intention was, however, to cross at Caperton’s Ferry—near Bridgeport and not far from Stevenson—and at Shellmound; these places are from twenty to forty miles below and to the west of Chattanooga. On August 20 at daybreak, Heg’s brigade, of Davis’s division of the Twentieth Corps, in which served the Fifteenth Wisconsin Infantry, crossed in pontoon boats at Caperton’s Ferry, drove away the enemy’s cavalry and occupied the southern bank. Here a twelve hundred feet pontoon bridge was soon completed, and Davis’s division of the Twentieth Corps, crossed and advanced to the foot of Sand Mountain, preceded by cavalry. Johnson’s division of the same corps crossed the following day on the same bridge. Sheridan’s division of the Twentieth Corps crossed at Bridgeport on a bridge constructed by them of pontoons and tressels; it was 2,700 feet long. Baird’s—formerly Rousseau’s—and Negley’s divisions of the Fourteenth Corps followed Sheridan’s division. The Twenty-first Corps marched down the Sequatchie Valley and crossed at Battle Creek, nine miles up the river from Bridgeport. Hazen’s, Wagner’s, and Wilder’s brigades were, as before mentioned, in the Tennessee Valley to the north of Chattanooga, and did not cross with their corps. The whole movement across the river began on August 29 and ended on September 4. The Third brigade of Van Cleve’s division of the Twenty-first Corps was left at McMinnville as a garrison. The railway was protected by the reserve corps; the Fourteenth Corps was ordered to concentrate in Lookout Valley and to send immediate detachments to seize Cooper’s and Stevens’s gaps of Lookout Mountain, the only passable routes to McLemore’s Cove, down which runs the west Chickamauga Creek in a northeasterly direction, towards Chattanooga. The Twentieth Corps was to move to Valley Head at the head of Lookout Valley, and seize Winston’s Gap forty miles south of Chattanooga. The Twenty-first Corps with the exception of Hazen’s and Wagner’s infantry and Minty’s cavalry—which were still north and east of Chattanooga—were to march to Wauhatchie, at the lower end of Lookout Valley, near Lookout Mountain, and to communicate with the Fourteenth Corps at Trenton in the same valley, and threaten Chattanooga by way of the Tennessee River via the nose of Lookout Mountain. The cavalry crossed at Caperton’s and at a ford near Island Creek, in Lookout Valley, from which point they reconnoitered towards Rome, Georgia, fifty-five miles south of Chattanooga, via Alpine. This last mentioned hamlet is forty-two miles south of Chattanooga. In the absence of Major-General Stanley—the chief of cavalry—its movements were not prompt. If the reader will refer to a good topographical map of the region around Chattanooga, he will see how sagacious these movements were, and what grand strategy they displayed. The Army of the Cumberland was stretched in line through the whole length of Lookout Valley, between Sand Mountain and Lookout Mountain, on the south side of the Tennessee River; it faced east towards the Chattanooga Valley, with only one range between them and the Confederate line of retreat and supplies; while on the northeast side of Chattanooga was a Union force of several brigades to prevent any counter movement by the Confederates upon the Union line of supplies.
After crossing the Tennessee River, Rosecrans continued his feints to make Bragg think that the real movement was the feigned one. He had sent Wagner’s infantry, and Wilder’s and Minty’s cavalry brigades to report to Hazen with a force amounting to about 7,000. Hazen caused the enemy to believe that the whole army was there, intending to cross the river above Chattanooga. This was done by extensive firings, marchings, countermarchings, and by bugle calls, at widely separated points; while Wilder moved his artillery continuously across openings in sight from the opposite bank.
The Confederates occupied in force the point of Lookout Mountain at Chattanooga. To carry this by an attack of the Twenty-first Corps seemed too risky; therefore the original movement was continued, namely, against the line south of Chattanooga, over Lookout Ridge, south of the point where it was held in force. The cavalry was ordered to advance on the extreme right to Summerville, in Broomtown Valley, a village eighteen miles south of Lafayette, Georgia. McCook was to support this movement by a division thrown forward to the vicinity of Alpine forty-two miles southwest of Chattanooga. These movements were made on September 8 and 9.
General Thomas crossed his corps over Frick’s, Cooper’s, and Stevens’s gaps of Lookout Mountain, to McLemore’s Cove.
These movements forced Bragg to evacuate Chattanooga on September 8. Then Crittenden with the Twenty-first Corps and its trains marched the same day around the point of Lookout and camped that night at Rossville, at the gap through Missionary Ridge, five miles south of Chattanooga. Through this gap runs the wagon road from Lafayette to Chattanooga.