James D. Porter, Confederate Military History, a library of Confederate States Military History: Volume 7.1, Tennessee
Clement Anselm Evans, Ed.

On the morning of the 27th the troops named retired under orders to Tullahoma, where General Bragg concentrated the army of Tennessee, taking position and determining to risk a battle; but the enemy pressed back his troops on the Manchester and Hillsboro road, and his communications with his base were temporarily destroyed. His health was very poor, and his corps commanders believing, as stated by General Hardee in a published letter, that he was not able ‘to take command in the field,’ advised him to retire. Acting upon this advice, the army abandoned Tullahoma, and on the 30th of June began the retreat, reaching Chattanooga on the 7th of July. Not a gun, or stores of any kind, was lost, and Polk's corps, largely composed of Middle and West Tennessee troops, was 400 stronger than when it retired from Shelbyville.

After resting at Chattanooga during the months of July and August, General Bragg, having received reinforcements of two small divisions from Mississippi, increasing the strength of the army, exclusive of cavalry, to 35,000, determined to attack the advancing enemy whenever an opportunity was offered. Without ability to garrison Chattanooga, the place was abandoned on the 7th and 8th of September, and the army took position from Lee & Gordon's mills to Lafayette in Georgia. Rosecrans immediately occupied the town and pushed forward in pursuit of Bragg, assuming that he was in retreat on Rome, but on the 10th discovered that the Confederate army was being concentrated about Lafayette. The Federal army was then at Gordon's mill, Bailey's cross-roads, at the foot of Stevens' gap, and at Alpine, a distance of 40 miles from flank to flank. General Bragg, who