[Footnote: General Bragg had here an opportunity to be shut up in Chattanooga, as Pemberton had been in Vicksburg; but, a more acute strategist, he knew the value of an army in the field to be greater than that of any fortified city.] Rosecrans pushed on in pursuit of Bragg, whom he supposed to be in full retreat. Bragg, however, having received powerful reinforcements, turned upon his pursuers so suddenly that they narrowly escaped being cut up in detail, while scattered along a line forty miles in length. The Union forces rapidly concentrated, and the two armies met on the Chickamauga. [Footnote: In the Indian language, the "River of Death"--an ominous name!] BATTLE OF CHICKAMAUGA (Sept. 19, 20).--The first-day's fight was indecisive. About noon of the second day, the Federal line became broken from the movement of troops to help the left wing, then hard pressed. Longstreet seized the opportunity, pushed a brigade into the gap, and swept the Federal right and centre from the field. The rushing crowd of fugitives bore Rosecrans himself away. In this crisis of the battle all depended on the left, under Thomas. If that yielded, the army would be utterly routed. All through the long afternoon the entire Confederate army surged against it. But Thomas held fast. [Footnote: Thomas was thenceforth styled the "Rock of Chickamauga." He was in command of men as brave as himself. Col. George, of the Second Minnesota, being asked, "How long can you hold this pass?" replied, "Until the regiment is mustered out of service."] At night he deliberately withdrew to Chattanooga, picking up five hundred prisoners on the way. The Union army, however, defeated in the field, was now shut up in its intrenchments. Bragg occupied the hills commanding the city, and cut off its communications. The garrison was threatened with starvation. [Footnote: "Starvation had so destroyed the animals that there were not artillery horses enough to take a battery into action. The number of mules that perished was graphically indicated by one of the soldiers of the army of the Tennessee: 'The mud was so deep that we could not travel by the road, but we got along pretty well by stepping from mule to mule as they lay dead by the way.'" --_Draper_.] [Illustration: VICINITY OF CHATTANOOGA.] BATTLE OF CHATTANOOGA [Footnote: In the Cherokee language, "The Hawk's Nest."] (Nov. 24, 25).--Grant having been appointed successor to Rosecrans, immediately hastened to Chattanooga. Affairs soon wore a different look. Hooker came with two corps from the Army of the Potomac; and Sherman hastened by forced marches from Iuka, two hundred miles away. [Footnote: Thomas held command after Rosecrans left, and Grant was afraid he might surrender before reinforcements could reach him, and therefore telegraphed him to hold fast. The characteristic reply was, "I will stay till I starve."]