The position occupied by the Army of the Cumberland had been made very strong for defence during the months it had been besieged.  The line was about a mile from the town, and extended from Citico Creek, a small stream running near the base of Missionary Ridge and emptying into the Tennessee about two miles below the mouth of the South Chickamauga, on the left, to Chattanooga Creek on the right.  All commanding points on the line were well fortified and well equipped with artillery.  The important elevations within the line had all been carefully fortified and supplied with a proper armament.  Among the elevations so fortified was one to the east of the town, named Fort Wood.  It owed its importance chiefly to the fact that it lay between the town and Missionary Ridge, where most of the strength of the enemy was.  Fort Wood had in it twenty-two pieces of artillery, most of which would reach the nearer points of the enemy’s line.  On the morning of the 23d Thomas, according to instructions, moved Granger’s corps of two divisions, Sheridan and T. J. Wood commanding, to the foot of Fort Wood, and formed them into line as if going on parade, Sheridan on the right, Wood to the left, extending to or near Citico Creek.  Palmer, commanding the 14th corps, held that part of our line facing south and southwest.  He supported Sheridan with one division (Baird’s), while his other division under Johnson remained in the trenches, under arms, ready to be moved to any point.  Howard’s corps was moved in rear of the centre.  The picket lines were within a few hundred yards of each other.  At two o’clock in the afternoon all were ready to advance.  By this time the clouds had lifted so that the enemy could see from his elevated position all that was going on.  The signal for advance was given by a booming of cannon from Fort Wood and other points on the line.  The rebel pickets were soon driven back upon the main guards, which occupied minor and detached heights between the main ridge and our lines.  These too were carried before halting, and before the enemy had time to reinforce their advance guards.  But it was not without loss on both sides.  This movement secured to us a line fully a mile in advance of the one we occupied in the morning, and the one which the enemy had occupied up to this time.  The fortifications were rapidly turned to face the other way.  During the following night they were made strong.  We lost in this preliminary action about eleven hundred killed and wounded, while the enemy probably lost quite as heavily, including the prisoners that were captured.  With the exception of the firing of artillery, kept up from Missionary Ridge and Fort Wood until night closed in, this ended the fighting for the first day.

The advantage was greatly on our side now, and if I could only have been assured that Burnside could hold out ten days longer I should have rested more easily.  But we were doing the best we could for him and the cause.