As has been said, the Army of the Cumberland lay along the western base of the mountains. On the 7th of September, Negley's division commenced the ascent of the steep sides, and at four o'clock in the afternoon gained the summit. A reconnaissance was made by Colonel Wood, and it was found that the enemy had heavy guns in the vicinity, covering the eastern side of the mountain. The next day General Negley seized Cooper's and Stevens' Gaps, finding the latter heavily barricaded. Other troops moved in various directions. The Riverlawns, with the cavalry on the extreme right, were ordered to sweep through Broomtown Valley and seize the railroad in the vicinity of Dalton, thus cutting off the enemy's line of communication in this district. The Riverlawns moved forward full of enthusiasm, and satisfied that at last some sort of a battle was at hand. But, alas! those hopes were doomed to disappointment. Bragg was leaving Chattanooga as fast as he could, and by the 9th of the month, everybody in the Army of the Cumberland knew it. Rosecrans had gained "The Gateway to Georgia," by strategy alone. As the enemy had retired, there was but one thing left to do,--go after him and compel him to either fight or surrender, and this Rosecrans did without a moment's delay. As Chattanooga was abandoned, General Crittenden took possession without serious opposition. The remainder of his troops were called up from the river, and on the same day that the news of the evacuation was spread around, he started with his corps for Ringgold, arriving at Rossville that evening. On the same day, Negley marched to McLemore's Cove, a split formed between Lookout Mountain and Pigeon Mountain, where he met the enemy's outposts and drove them back for several miles. At the same time Heg's brigade marched into Broomtown Valley, to support the cavalry, should they be needed. The pursuit was growing warm, and the next day the advance of the Union troops was checked in several places and severe skirmishes resulted. General Bragg had left Chattanooga in haste, but had no idea of retreating without a battle. He reckoned that the Union forces were larger in numbers than his own, and he devised a plan for meeting them not as a whole but by columns. The Confederate's first combination was directed against the corps under General Thomas. If he could reach and crush Thomas's force before the others could come up, he felt the remainder of the campaign would be comparatively plain sailing. The division under Negley at McLemore's Cove was not allowed to rest, for Bragg ordered a movement against it in great force.