The Confederates crossed the Chickamauga, and, on the morning of the 19th, Rosecrans opened the battle by attacking the enemy's right wing. The entire armies were soon involved, and the fighting lasted until nightfall, with the result in favor of the Confederates. Although forced from several positions, they gained and held the road leading to Chattanooga, and the Union troops were driven almost to the base of Missionary Ridge. Late that night, Longstreet arrived with his fire-seasoned veterans. He was one of Lee's best lieutenants, and it was arranged that the battle should be renewed the next morning at daybreak, with Longstreet commanding the left wing. From some cause, the Confederate attack was delayed until ten o'clock, the delay giving the Federals time to throw up a number of breastworks. Against these Bragg repeatedly charged with his right wing, but was repulsed each time. Thomas, in command of the Union left, also repelled a sharp attack, but Longstreet routed Rosecrans, and, discerning a gap caused by the transfer of the Union centre to strengthen the left, Longstreet led his men impetuously into the opening, thus splitting the Union army in two. Striking in both directions, he threw the two divisions into such disorder and confusion that the frightened Rosecrans galloped in hot haste to Chattanooga to secure his supply train and the pontoon-bridges over the Tennessee. At the same time, he telegraphed the terrifying tidings to Washington that the whole Union army had been beaten. "THE ROCK OF CHICKAMAUGA." At a crisis in the tremendous battle, General Hood, one of the Confederate leaders, was wounded, and a halt was made until another officer could be brought up to take his place. Short as was the delay, it gave the Unionists time to rally and strengthen their endangered points. Despite this advantage, the telegram of Rosecrans would have been verified and the magnificent army destroyed except for one man. He was George H. Thomas, the heroic commander of the Union left. Longstreet launched his veterans against him again and again, but he beat them back in every instance. Never did men fight more bravely than those Americans, arrayed against each other, and never was finer generalship displayed than by General Thomas, whose wonderful defense that day won for him the name by which he will always be remembered--"The Rock of Chickamauga." [Illustration: GEORGE H. THOMAS. "The Rock of Chickamauga."] Holding his heroes well in hand, Thomas was ready to renew the battle the next day, but Bragg did not molest him. The Confederates, however, had won a victory, for they drove the Federals from the field and retained possession of it. Thomas fell slowly back toward Chattanooga, presenting a firm front to the enemy.