Sunday, the twentieth of September, proved an eventful day to the Army of the Cumberland. The sun rose bright and clear, but an impenetrable mist hung over the field between the two hostile armies. General Rosecrans was anxious and alarmed, from the fact that, at the close of the preceding day, there were only two of his brigades which had not been brought opportunely and squarely into the action. This convinced him that he was greatly outnumbered, and he must now fight, not only for the position of Chattanooga, but for the very existence of his army. The corps commanders met at headquarters, at Widow Glen’s house, and, after participating in long and grave consultation, received orders for the disposition of the troops for the following day. General Thomas, with his reinforcements, was to maintain the line he had assumed, with Brennan in reserve; General McCook, when his pickets were driven in, was to close on Thomas, and enclose the position at Widow Glen’s house. Crittenden with two divisions in reserve, near the junction of Thomas’s and McCook’s lines, was to place himself in position to succor either. But McCook stationed his troops too far on the crest, and the reserve under General Davis was removed to a wooded hill side, west of the Dry Valley road, instead of being placed in close column in a sheltered position more to the left. General Crittenden was in the valley close by, too far to the right, and the indispensable necessity of keeping near to the left where the enemy’s first assault might be expected, was not sufficiently regarded. General Negley withdrew his reserve brigade from the line and joined General Thomas, but General Crittenden failed to relieve him. Wood’s troops were, however, finally moved into the position vacated by Negley’s reserves; but the delay proved of serious consequence, for the battle had already begun, at half past eight A. M., on the extreme left, as was expected. General Thomas sent for Negley’s remaining brigades, and as he continued to be hard pressed. Van Cleve was sent to his assistance. General Reynolds’s right was now found to be exposed, by an opening in the line, to the enemy. General Wood was ordered to close up on Reynolds, and General Davis on General Wood, and General McCook to concentrate his whole command to the left. General Wood, however, withdrew from the line and passed to the west of General Brannan, who was in echelon, thus opening in the line of battle “A gap for ruin’s wasteful entrance,”