CHICKAMAUGA, Battle of, fought near Chickamauga Creek, and on Geor gia soil, 19-20 Sept. 1863. General Rosecrans (q.v.) having forced Bragg (q.v.) out of his fortified position in Middle Tennessee by a campaign of strategy, prepared to gain pos session of Chattanooga, the gateway through the mountains to the Gulf States, and a most important railroad centre for the Confederacy. Bragg held the city. Rosecrans' army lay along the western base of the Cumberlands, with headquarters at Winchester, Tenn. His army was composed of three corps of infantry, the Fourteenth, Gen. George H. Thomas; the Twentieth, Gen. Alek. McD. McCook; and the Twenty-first, Gen. Thomas L. Crittenden. Gen.
D. S. Stanley commanded the one corps of cavalry. McCook's corps was the right wing, Thomas' the centre and Crittenden's the left. Stanley's cavalry guarded the right flank and Minty's brigade of cavalry the left.
The plan of campaign involved the repair of the railroad to the Tennessee River, the collection of supplies for a month's absence from any base, and ammunition for two battles and the throwing of Rosecrans' army to the rear of Chattanooga and advancing to it from the south. His centre and right were ascend ing Lookout before Bragg became aware of the character of the movement. He then evacuated Chattanooga and moved to La Fay ette, 26 miles south and behind Pigeon Moun tain, the next range east of Lookout, leaving his rear-guard just below Lee and Gordon's Mill at the crossing of the Chickamauga. Crittenden having accomplished his purpose north of the Tennessee withdrew through Sequatchee Val ley to the river, crossed both that and the Sand Mountains and entered Lookout Valley near the north point of Lookout Mountain. A reconnoitering party, 9 September, discovered the evacuation of the city. Passing around the point of the mountain, Crittenden, leaving one brigade in the city, proceeded at once, by way of Rossville Gap, to operate to the left of Thomas, who had descended Lookout at Ste vens' Gap. McCook was further to the right, having crossed Lookout at Winston's. The grand strategy of the campaign had been en tirely successful. The army had been thrown over three formidable mountain ranges and a wide river, all within the immediate territory of General Bragg, without opposition, almost without discovery and entirely without loss. To possess Chattanooga it remained necessary to concentrate the widely separated corps in it, or between it and Bragg.
Erroneous dispatches led Rosecrans to be lieve that Bragg was retreating on Rome. He ordered pursuit, awl found Bragg occupying the gaps in Pigeon Mountain in force and pre paring movements against each separate corps.
These failed, and Bragg, having notice of the arrival of Longstreet, with two divisions from the Army of Northern Virginia, issued, 18 September, orders of battle designed for inter posing between the Union army and the city. At this time the main bodies of the two armies confronted each other across the upper Chicka mauga, and Longstreet was arriving at Ring gold. Crittenden's corps was concentrated at Lee and Gordon's Mill.
During the afternoon of the 18th Gen. Bush rod Johnson from Ringgold, in command of five brigades, including Hood's division of Longstreet's corps, forced a crossing at Reed's Bridge, after a sharp defense by Minty's cavalry. Walker's corps, after failing at Alex ander's Bridge, which was defended by Wilder's brigade of mounted infantry, crossed at a ford below. During the night about two thirds of Bragg's army crossed the Chicka mauga, and early in the morning of the 19th, he formed line of battle directly on Crittenden's left flank and in contact with it. Bragg's plan was to drive Crittenden's corps back on Thomas in the centre, and both on McCook at the right, and force the whole into the mountain. His plan of battle was interfered with and finally destroyed by an undiscovered night advance of Rosecrans' centre and right, by which he passed several miles beyond Bragg's position and thrust his lines across the La Fayette road and eastward to the Chickamauga, and so gained position between Bragg and Chattanooga. The head of Thomas' corps, which struck Forrest's cavalry at Jay's Mill, was Brannan's division. The fighting, desperate and at close quarters, continued until 1 o'clock, when Forrest and his supports were repulsed. Soon both armies were rapidly advancing toward this vortex of fierce fighting. It was of desperate character on both sides, continuing from noon until sun set, with alternate success and repulse for each side, the field finally remaining in possession of the Union forces. The fighting throughout the day had been largely in forests thick with un derbrush, and so all within the limits of point blank range. At nightfall Cleburne's division burst with great force upon the lines of John son's and Baird's divisions, which were well in advance at the centre. 'They gradually with drew from under the fire which continued for an hour after dark. At the close of the fighting for the day Rosecrans' army held La Fayette road between Bragg and Chattanooga, and Bragg's plan of battle for the day had been effectually defeated.