But through a series of well-rehearsed feints, Rosecrans captured the key passes, helped by the use of the new seven-shot Spencer repeating rifle.

The campaign ended in the same week as the two historic Union victories at Gettysburg and Vicksburg, and Rosecrans complained that his achievement was overshadowed.

However, Confederate casualties had been few, and Bragg's army soon received reinforcements that enabled it to defeat Rosecrans at the Battle of Chickamauga two months later.

[1] Bragg, headquartered in Tullahoma, was concerned that Rosecrans would advance to seize the strategic city of Chattanooga, a vital rail junction and the gateway to northern Georgia.

His cavalry was spread over such a wide front because he was also concerned at a tactical level that Rosecrans might be able to turn his position, forcing him to retreat or to fight at a disadvantage.

He received numerous entreaties from President Abraham Lincoln, Secretary of War Edwin M. Stanton, and General-in-Chief Henry W. Halleck to resume campaigning against Bragg, but rebuffed them through the winter and spring.

A primary concern of the government was that if Rosecrans continued to sit idly, the Confederates might move units from Bragg's army in an attempt to relieve the pressure that Union Maj. Gen. Ulysses S. Grant was applying to Vicksburg, Mississippi.

The area his troops occupied, known as the Barrens, was a zone of poor farmland that made it difficult for him to obtain subsistence for his army while he waited for Rosecrans to attack him.

"[9] Johnston explicitly refused any suggestion that he take command, concerned that people would think he had taken advantage of the situation for his own personal gain.

[5] On June 2, Halleck telegraphed that if Rosecrans was unwilling to move, some of his troops would be sent to Mississippi to reinforce Grant, who by then was besieging Vicksburg, but was potentially threatened by the army of Joseph E. Johnston in his rear.

[18] The Union Army of the Cumberland, commanded by Rosecrans, began campaigning with 50–60,000 men,[i] composed of the following major organizations:[19] The Confederate Army of Tennessee, commanded by Bragg, with about 45,000 men,[ii] was composed of the following major organizations:[20] The first movements of the campaign had actually begun on June 23 when elements of the Reserve Corps under Granger, with a cavalry division under Mitchell, moved due west from Murfreesboro to Triune to begin an elaborate feint.

[22] Rosecrans's elaborate plan, which would test the extensive training program he had spent the six months conducting, was to slide Granger's corps to the left, covering the Shelbyville approaches, and perform a giant right wheel of the army.

While Bragg's attention was focused on the strongly fortified Shelbyville, Thomas's corps would march southeast on the Manchester Pike, headed for Hoover's Gap on Hardee's right flank.

[23] During the spring, Rosecrans had repeatedly asked for more cavalry resources, which were denied by Washington, but he did receive permission to outfit an infantry brigade as a mounted unit.

Wilder's brigade had the mobility and firepower, but also the high unit morale, necessary to lead the surprise advance on Hoover's Gap before it could be reinforced.

[24] Our regiment lay on the hill side in mud and water, the rain pouring down in torrents, while each shell screamed so close to us as to make it seem that the next would tear us to pieces.

Their opponents, the 1st Kentucky Cavalry, skirmished briefly and withdrew under pressure, but were unable to reach the gap before the better-fed horses of the Lightning Brigade.

The Kentuckians fell apart as a unit and failed in their cavalry mission to provide intelligence of the Union movement to their higher headquarters.

Although Wilder's main infantry support was well behind his mounted brigade, he determined to continue pushing through the Gap and hold it before the Confederate reinforcements could arrive.

Wilder's brigade held the Gap until the main infantry units of the XIV Corps arrived to secure the position against any further assaults.

The corps commander, General Thomas, shook Wilder's hand and told him, "You have saved the lives of a thousand men by your gallant conduct today.

A frontal assault against the breastworks was not feasible, so a fierce battle of flanking maneuvers resulted against the Confederate brigades of Brig.

)[28] This slowed the Union advances, but the day was marked by the Army of the Cumberland's "absolutely flawless execution of Rosecrans's plan."

The mistrust among the general officers of the Army of Tennessee for the past months led to little direct communication about strategy and neither Polk nor Hardee had a firm understanding of Bragg's plans.

Hardee complained about the unsuitability of the Tullahoma position, but rather than assuming that Bragg and Joseph E. Johnston understood the strategic situation and that he had insufficient knowledge of their plans, as historian Steven E. Woodworth described it, "He simply took the situation as further proof of his long-held notion that Bragg was an idiot" and pursued the course "he deemed best for saving an army whose commander was an idiot.

Some resistance remained and Col. Robert H. G. Minty personally led his "Saber Brigade" of Michigan cavalrymen in a mounted charge over the breastworks after the retreating Confederates.

The rain-swollen Elk River proved a significant obstacle, but they disassembled a nearby mill and constructed a raft to float their howitzers across.

The next morning they rode into the foothills of the Cumberland Mountains, reaching the town of Sewanee, the place Leonidas Polk had selected a few years before as the future site of the University of the South, where they destroyed a branch rail line.

[36] The Army of Tennessee took up positions below the Elk River, but Hardee and Polk convinced Bragg to move farther south, to the town of Cowan.

Rosecrans was infuriated by this attitude and responded, "Just received your cheering telegram announcing the fall of Vicksburg and confirming the defeat of Lee.