of the Artillery Battalion, under Lieutenant Richard Goldthwaite. Battle Arriving at his lookout point from the depot, Hooker saw a small line of infantrymen and decided to deploy his forces into the gap without his artillery. Under the command of General Charles Woods, his brigade entered the gap, but were quickly driven back by Granbury's unit. The Confederates held their fire until the Union line was fifty yards away. Upon Cleburne's orders, Goldthwaite's men fired three shots from the disguised twelve-pound Napoleon cannons while the rest of the Army of Tennessee exchanged fire with the bluecoats. Believing they could gain a tactical advantage, Woods sent the 13th Illinois right to seek shelter in the buildings of Jobes Farm. After another failed attempt against Cleburne's troops, Woods' troops were halted by gunfire from Taylor's Ridge and cannon fire from within the gap. To counter the opposition, Osterhaus sent the 76th Ohio and 4th Iowa to attack the Confederate forces on Taylor's Ridge. The initial volley disorganized Osterhaus's division and his Union forces were unable to advance from their position for the remainder of the battle. John Geary's XII Corps division was the next to arrive around 10:40a.m. Under the command of David Ireland, one brigade again attacked the Confederate right while another regiment attacked the gap. As they moved further into the gap, both forces were halted by heavy Confederate fire from Taylor's Ridge and White Oak Mountain. Simultaneously, William Creighton and Orrin Crane's 1st Brigade was sent to support Williamson's 2nd Brigade on White Oak Mountain. The brigade was driven back by Polk and Lowrey's regiments, and Creighton was killed during an attempt to rally his men against the Confederates. After holding his position for five hours, Cleburne received communications from Bragg around 12:00 p.m. notifying him that the army had made it safely through the gap and he could begin his retreat. Leaving skirmishers along his front to hide his withdrawal, he pulled back from the gap about 2:00p.m. and burned the bridge on the eastern side of the gap. Grant arrived near the gap, and the scattered position of his army made him decide to return to Chattanooga; no further Union pursuit was organized. Aftermath Cleburne had lost 20 killed and 201 wounded during the battle. Union casualties totaled 509 killed and wounded. Although Hooker was severely criticized for his conduct of the battle by Union Assistant Secretary