[Illustration: Two of the Confederacy’s celebrated cavalry leaders were Nathan Bedford Forrest and John Hunt Morgan. Forrest was a semi-illiterate with no prior military training. But he became a fearless fighter and an unequalled cavalry commander.] [Illustration: Morgan led an independent group of horsemen known popularly as “Kentucky Cavaliers.” He was ambushed and killed at Greenville, Tenn., in 1864.] On the other hand, Gen. Bedford Forrest and his Confederate cavalry made a series of quick attacks in Tennessee throughout March and April. Gen. John Hunt Morgan followed this with a summer foray through Kentucky, southern Indiana, and across Ohio. Throughout the first half of 1863 Grant slowly tightened the noose around Vicksburg. Moving down the west bank of the Mississippi and crossing below Vicksburg, Grant won clear victories at Port Gibson (May 1), Raymond (May 12), Jackson (May 14), Champion’s Hill (May 16), and Big Black River (May 17). On May 18 Grant began his siege of Vicksburg itself, and for six weeks the Federals isolated Gen. John C. Pemberton and his Vicksburg defenders. Confederate soldiers inside the besieged city eventually found it necessary to eat rats, mules and grass in an effort to stay alive. With escape hopeless, Pemberton on July 4 surrendered Vicksburg. Not only did Grant capture an entire Southern army of 30,000 men, but the mighty Mississippi, from Minnesota to the Gulf, lay in Federal hands. The North had severed Missouri, Arkansas, Texas, and most of Louisiana from the Confederacy. As Grant was accepting the surrender of Vicksburg, Gen. Rosecrans and his Federal army of 60,000 men were pushing forward in middle Tennessee. Rosecrans forced Bragg’s army of 47,000 Confederates out of Tullahoma and across the Tennessee River. The Federals slowly began to envelop the key city of Chattanooga. Bragg, in fear of being flanked, retreated into Georgia. Rosecrans seized the strategic rail center, then started in quest of Bragg’s army. This brought on the desperate battle of Chickamauga (September 19-20). On the first day Bragg attacked but failed to break Rosecrans’s line. That night Gen. James Longstreet arrived from Lee’s army with fresh Confederate troops. Bragg renewed the attack the following morning. After several hours of intense fighting, the Confederates pierced the Federal lines. Rosecrans’s right flank, and the general himself, retreated in disorder to Chattanooga. But the Federal left held fast until darkness ended the conflict. [Illustration: Confederate troops at Chickamauga tried desperately to rout the Federal army, but a determined stand by blueclad soldiers under Virginia-born George H. Thomas, the “Rock of Chickamauga,” prevented a complete collapse.] [Illustration: George H. Thomas.]