Washington, August 14.—[Special.]—The last letter in this series left the Army of the Cumberland on the morning of the 19th of September, concentrated for battle on the field of Chickamauga. By an energetic night march the army had been thrown forward on its left by inversion into line, and thrust between the enemy and Chattanooga, the objective of the campaign. It was a difficult and dangerous movement, where two armies, intent on battle, were only separated by such a stream as the Chickamauga, which was everywhere easily fordable above Lee & Gordon's. But General Thomas, who led this column, is the one commander of a great army of whom it can be said with accuracy that from the first of the war to the close no movement of his miscarried. At daylight of the 19th he held the Lafayette and Chattanooga road at the Kelly farm.
Bragg's army, though re-enforced from all parts of the Confederacy, and though it had been well concentrated between Lafayette and Gordon's mills for several preceding days, had been skillfully foiled by General Rosecrans in the efforts to strike his isolated corps. During the 18th it had been pressed by Bragg down the winding and thickly-wooded valley of the Chickamauga in execution of an order for battle. This order was based upon the idea that Crittenden's corps at Lee & Gordon's was the left of the Union army. While he was to be held there by strong force threatening attack from the other side of the stream, the bulk of Bragg's army was to cross at the various fords and bridges below, and, turning up stream, was then to join in sweeping Crittenden back on Thomas and McCook, whom Bragg supposed still to constitute the Union center and right. In execution of this plan Bushrod Johnson had crossed at Reed's bridge, and pushed up to within a mile and a half of Lee & Gordon's, and westward to within a mile of the Lafayette road, where night overtook him. Walker's corps had crossed below Alexander's Bridge, and bivouacked after a short advance toward Crittenden. Minty and Wilder, with their mounted men, and Dan McCook, with his brigade, had stoutly resisted and greatly delayed these columns. The most of Bragg's army had rested through the night. Two corps of Rosecrans's forces had marched continuously since four o'clock the preceding afternoon. They were about to move into battle without time for breakfast or further rest. Bragg, upon Longstreet's arrival, would have 70,000 men available for the fight. Rosecrans's strength for battle was not over 56,000.
At daylight all of Bragg's army, wholly concealed by the forests, was in motion. A considerable portion of it was still crossing the river at the various fords and bridges from Tedford's to Reed's bridge, and deploying on the other side toward Crittenden, who was still supposed to hold the Union left.
Suddenly, about 9 o'clock, there came to Bragg's ears the sounds of heavy and unexpected battle far down the Chickamauga and well toward Rossville. Thomas, whose head of column rested at the Kelly farm, for the double purpose of exploring the forests in his front and to test the truth of a report that an isolated brigade of the enemy was on the west side of the river near Reed's bridge, moved Brannan and Baird directly into the forest on the road towards Reed's. At this time two-thirds of Bragg's army, concealed by the forests, had crossed the Chickamauga and was directing its columns up that stream toward Crittenden. Just at the time when Bragg expected that his right would have swung across the Lafayette road, and that his center divisions would have opened on Crittenden's position at Lee & Gordon's, these portentous sounds of battle from Thomas's line astonished and perplexed him. After vainly waiting for them to cease, under the first impression that the affair was a movement of his forces in reconnaissance, and that some Union cavalry had been encountered, he found it so serious as to derange his whole plan of battle, and force him to meet an enemy who had turned his right. To do this he was obliged to move a portion of his troops that had not crossed the river down stream to Reed's. By the circuitous roads which they were obliged to travel, it required a march of six miles to reach the left of Thomas.
This destruction of the rebel plan was due to Thomas opening the battle with the divisions of Brannan and Baird in the vicinity of Reed's bridge. At 6.30 o'clock Brannan left Kelly's, and moving north, turned in from the Lafayette road at McDaniel's toward Reed's. A quarter of a mile from McDaniel's he deployed his division. Van Derveer was on the left, and thus became the left of the Union army. Connell's brigade was in the center, and Croxton on the right. In like manner Baird advanced with a front line of two brigades. King, with the regulars, was on the left, next to Brannan, and Scribner on the right of King, while Starkweather marched by the flank behind Scribner's right.
The last disposition was promptly made by Baird upon his discovering that the enemy was in strong force to his right.
Thus while neither army was aware that the other was in heavy force in the woods which surrounded them, and while Bragg's forces were forming to move up the Chickamauga, and so away from Thomas's line of march, both Brannan and Baird came in force on Bragg's right, in front of Reed's bridge, at a point near Jay's Mills, and opened the battle of Chickamauga. Croxton struck first with a vigorous attack on Forrest, who, with the two divisions of his corps, was guarding the Confederate right. The cavalrymen were forced back to the sawmill, where they rallied, dismounted, and began to fight as infantry. Croxton held his own, and even advanced slightly. Forrest sent for infantry, and Wilson's brigade of Walker's division hurried from Alexander's and rushed into the fight.
Meantime re-enforcements were turning from all portions of Bragg's line toward the sound of furious battle. Shortly the advance toward Crittenden ceased, so vigorous had Thomas's battle become. Connell and Van Derveer at first meeting no enemy on their fronts pressed toward the vortex of Croxton's fighting. Forrest, relieved by Walker's infantry, met this advance of Brannan's left with his whole force and fought for the most part on foot. Croxton, out of ammunition, was obliged to retire somewhat before Walker, when Baird pushed King in to support him, while Van Derveer and Connell moved in first on Forrest and next on Ector's brigade of Walker's reserve. The battle became terrific. Forrest hurried in person after infantry supports, and for portions of his own command left near Alexander's.
At 11 o'clock Bragg had become convinced that Rosecrans had forced battle upon him on the extreme rebel right. With such vigor did Thomas's two divisions fight that Walker was ordered at that hour to go to Forrest with all his force, and Cheatham, of Polk's corps, who had the strongest division of the army, consisting of five brigades, then stationed as the reserve of Bragg's left. Hardly had Cheatham started before Stewart, of Buckner's corps, which was near Tedford's Ford, ready to move toward Crittenden, was also dispatched in haste to the Confederate right, and at 1 o'clock Cleburne, of Hill's corps, posted near the extreme left of the Confederate line, was ordered to the scene of action before Brannan and Baird. These movements show how Bragg's plan of battle had been wholly overturned, and how fierce the fighting of these two divisions of Thomas must have been to decide Bragg to send four infantry divisions to the assistance of Forrest's corps of two divisions.
Meantime Walker had moved Govan's brigade obliquely on the right flank of Scribner and forced him back. Simultaneously Walthall's brigade struck King in flank and drove him in disorder over Van Derveer's brigade. Guenther's regular battery, one of the best and most efficient in the service, was captured. We shall see how it was shortly after retaken by the splendid Ninth Ohio.