Union forces defeated at Chickamauga Creek were besieged in Chattanooga, pinned down by Confederate forces perched on the high ground pictured here. Grant was summoned to avert an impending disaster and restore a demoralized army. After sizing up the situation, he directed George Thomas to attack the center of Braxton Bragg's defensive line. By taking advantage of mistakes made by his foes, Grant orchestrated what became a rout. He had forged yet another major turning point in the war.