Under cover of Crittenden's feint, the rest of the Union army moved to its assigned places, and crossed the Tennessee between August 29th and September 4th, getting into touch with the Confederate outposts on the 6th. On the 9th, Rosecrans heard that Bragg had evacuated Chattanooga and gone south: he ordered McCook's corps to strike across and cut off his retreat, but on the 11th the passes were found blocked, the advanced troops could not get forward, and definite information came in that Bragg's army was concentrated right in front, at the exit from the mountains, and that he was expecting Longstreet's corps from Virginia. This was serious, for the Union army was scattered over a front of some thirty miles, in a maze of valleys, with very bad going, and worse communication between them, and under these unfavorable circumstances it was vital to concentrate it at once. Rosecrans had made a rash and badly calculated move, and was caught in the middle of it.
Bragg saw his opponent's mistakes, on the 8th, both in thinking that he was in retreat, and in his loose dispositions, and gave orders which would have exposed the Union army to defeat in detail, but he was on bad terms with his subordinates, who delayed, and gave Rosecrans the time he wanted. Bragg ordered a concentration on the east bank of the Chickamauga, keeping up a cavalry screen till Longstreet arrived from Virginia, which he did on the 18th and 19th, without cavalry or artillery. Bragg issued his orders on the 18th for the battle next day, intending to destroy the Union left, seize the Lafayette road, and cut Rosecrans off from Chattanooga. His corps were to advance in succession from the right, outflanking the Union left, and turning to the left as they crossed the river, so as to drive the Union forces southward up the valley from Polk's front: Polk, the left corps but one, who was really facing the bulk of the Union army, to push forward and join in the attack. D. H. Hill, on the left, was to cover that Rank by attacking Rosecran's right. These movements were not carried out as soon as they should have been, partly owing to the bad ground and the unexpected resistance of the Union outposts, but partly also to the dilatoriness of some of the commanders.
Between the 12th and 18th, Rosecrans was concentrating, some of his troops being far to the south at McAlpine, and on the 18th he sent Thomas to occupy the important Lafayette road. He held the line, Crawfish Springs-Lee and Gordon's Mills-McLennon's Cove, the general line being along the Chattanooga-Rossville road. The whole army was in position about daybreak on the 19th. He told Thomas, when be sent him to the left, that he was to hold the Rossville road, and that, if hard prest, the whole army would come to his help. On this day, 18th, there were some movements near the fords, and Thomas took more ground to his left. Next day, Thomas moved first, and Bragg found that instead of outflanking his enemy, he was outflanked himself, and was attacked instead of attacking, for a sharp fight began before his troops were in their places. Both sides brought up supports, and the battle swayed backward and forward. Bragg, seeing that Rosecrans had discovered his plan, and would fight for the Rossville road, put Polk in command on the right, supporting him with Hill's corps. A furious attack drove Thomas back and reached the Lafayette road, but it was recovered, and Thomas took up a more compact position. Granger, with three brigades in reserve, was at Rossville, covering the rear and left. The first day's battle was in favor of Rosecrans, for Bragg had failed to shake his hold on the important roads.
For the next day, Bragg, now that all Longstreet's force was in, divided the army into two commands, under him and Polk, on the left and right respectively. The attack was to be made in echelon from the right, at dawn: when in action, the whole army was to wheel to the left, but also to press the Union left, to seize the Chattanooga road.
Rosecrans's plans for the 20th were for Thomas to hold his old position and the Rossville road; McCook to hold his advanced line as long as possible, touching Thomas with his left, Crittenden to be in reserve in rear of the center. All the troops were not in their places at daybreak, and Rosecrans found much fault with McCook's disposition, directing him to alter it. Much time was lost in making these corrections.
On the other side, Bragg came up and found the attack hanging fire, and Polk not present. He saw that Thomas was not holding the Chattanooga road strongly, and threw a heavy attack on it, which was repulsed, but he now put his whole weight in here, and Thomas had to call on McCook for reenforcements till a thin place was made in the line: before it could be made good, Longstreet burst in with one of his tremendous attacks, with five divisions, broke the line, and cut the Union army in two on Thomas's right, while Bragg again attacked on his left, to cut him off from Chattanooga, but was again repulsed.
Longstreet, however, now saw that the conditions warranted a departure from the original plan of battle, and instead of wheeling to his left, to drive McCook up the valley, turned to the right on Thomas, Crittenden's men had all been thrown into the fight, and Granger's command at Rossville was the last reserve; he had been told to stay there, to cover the rear, but saw also that his orders were not longer applicable, and moved up in the nick of time to save Thomas from defeat. Longstreet's last reserve was all that remained on the other side, and Bragg threw it in for a last furious attack, which failed, and when night fell Thomas was still holding his ground.
Just before Longstreet's attack, Rosecrans had gone to look after things on the right, and could not return to Thomas except via Rossville. He there heard that the army was beaten, and made the fatal mistake of not going to see for himself, but to Chattanooga, to make arrangements for his beaten army, sending to tell Thomas to take command on the field, and retreat to Rossville. Thomas, however, determined to hold on till dark, and did not move till all attacks had been beaten off.2 He then took post at Rossville Gap till all was ready at Chattanooga, when the whole army was brought there, and works thrown up which protected it from direct attack.
Tho Rosecrans' full strength was 67,500 men, his long line took so many to guard it that he had no more than 55,000 on the field, out of which he lost 11,080 in killed and wounded, missing 5,255; total, 16,335. Bragg had some 70,000 men in action; his losses were believed to be 2,673 killed, 16,274 wounded, 2,003 missing; total, 20,950.
Up to the time that Bragg left Chattanooga, Rosecrans had outgeneraled him at every point: it was a most masterly performance to turn out a man of his caliber, first from Tennessee, then from his base, in such a way, but the calculations for the campaign which ended at Chickamauga do not seem to have been so carefully worked out as before. . . .
This was one of the hardest battles of the whole war, of which it was said that neither side ever fought so well. D. H. Hill says that the "barren victory" broke the Confederates' hearts, and that their dash was never again seen to perfection. Bragg had again fought his army to a standstill against the great Rosecrans-Thomas combination, and lost his objective, Chattanooga. Both sides lost by the campaign, Rosecrans tactically, Bragg strategically.
Great was the consternation in the North at the news. Reenforcements were hurried up from all sides: Hooker went from the East, with the Eleventh and Twelfth Corps, 15,000 strong; Sherman and Hurlbut sent troops from Vicksburg and Memphis, and Burnside moved forward. Rosecrans was in a most precarious position, down in a hole, with approaches from north and northwest over sixty miles of rough mountain tracks, and these made insecure by Confederate cavalry, while his regular line of supply from the west passed through the Tennessee Valley, which his enemies commanded. The railway to Knoxville was useless, owing to Confederate operations, and Chattanooga was a wretched position, commanded from all sides. Bragg was thus certain that the Union troops must soon evacuate it, unless help came.
The news from Chattanooga became worse and worse, for retreat would have meant not only the loss of all Rosecrans' guns, but of the army itself as an organized body, such a disaster, in fact, as had not yet been incurred, which would have gone far to neutralize the results of Gettysburg and Vicksburg, and to avert which a stronger hand was wanted. Grant was put in command of the country between the Alleghanies and the Mississippi, with the exception of Banks' district, and chose the scheme of reorganization which substituted Thomas for Rosecrans. McCook and Crittenden were also relieved from command. The Twentieth and Twenty-first Corps were made into a new Fourth and put under Granger, Sherman and Hurlbut were hastening up, and things looked better. Grant at once took up the shortening of the line of supply, by river, and a new bridge, near Wauhatchie, covered by Hooker's command, and when it was opened, on November 1st, Thomas's army had only two or three days' rations left.
At this time Bragg sent Longstreet away against Burnside, at Knoxville, which seems a huge mistake, to send away his best lieutenant and two divisions, just before an important campaign, but the reason was that they could not pull together, and Jefferson Davis came down, it is supposed, to settle the trouble. Grant, who knew both men well, was not surprized, for Bragg was most quarrelsome, and Longstreet would not be put upon. When he heard that Longstreet had gone, he planned to attack Bragg's position as soon as Sherman came, for he wished him to take the principal attack, as he thought that Thomas's army was rather demoralized. The weather was so bad that Sherman did not arrive tell the 21st: he was to attack Missionary Ridge, supported by part of Thomas's command, the rest making a feint of attacking from Chattanooga, Hooker to hold Lookout Valley, and Howard's Eleventh Corps, north of the river, held at disposal.
On the 23d, Thomas was sent to make a reconnaissance in force, to see whether Bragg was sending men away or retreating: he gained some ground on the side of Missionary Ridge, and entrenched it, while Sherman attacked the north end of the hill, with the same result. Sherman was ordered to attack at dawn on the 24th, and was told that Thomas would do the same, Hooker making a demonstration against Lookout Mountain. The day opened thick and wet, and the Confederates on the high ground could not see what was going on below, which helped Hooker, who pushed up Lookout Mountain, above the clouds, cleared the near end of it, and drove the Confederates down the other side: he entrenched where he stood. On the 25th he went on to Rossville, chasing the enemy till dark, from there, and from their works on the battle-field of Chickamauga.
On this day, Sherman made his main attack on Missionary Ridge, but was stoutly opposed, till Grant told Thomas to take four divisions, seize the first line of rifle-pits in his front, and await orders, but instead of this they charged right up the steep hill and cleared it, because the fire on the first line of works taken, from those in rear, was so severe that they were less exposed if they went on up the steeper part of the hill. Tho this part of the Confederate main line was very strong, Bragg sent for reenforcements as soon as he saw the move, but the Army of the Cumberland would not be denied, and swept over all with hardly a check, driving his troops back beyond Chickamauga Station. In the night he withdrew his troops from Sherman's front, and Sherman occupied their ground: the pursuit was kept up till the 28th, and the railway to Atlanta destroyed in many places.
This great victory of Chattanooga enabled Grant and Sherman to plan the stroke which should sweep through the heart of the Confederacy and bring home to its people the meaning of war, at their own doors: the first stage being the advance to Atlanta, the great railway and manufacturing center of the South, to be undertaken the next spring.
1 From Formby's "American Civil War." By permission of the publishers, Charles Scribner's Sons.
2 General George H. Thomas's share in this battle gained for him the title of "The Rock of Chickamauga."