 Complete the following phrase:  During the American Civil War, Chattanooga was a center of battle. Chattanooga served as a hub connecting fifty percent of the Confederacys arsenals, those being located in Atlanta, Augusta, Columbus, and Macon. Chattanooga railroads proved vital in the Confederacys transportation of raw material to processing plants where they were responsible for producing small arms munitions. During the Chickamauga Campaign, Union artillery bombarded Chattanooga as a diversion and occupied it on September 9, 1863. Following the Battle of Chickamauga, the defeated Union Army retreated to safety in Chattanooga. On November 23, 1863, the Battles for Chattanooga began when Union forces led by Major General Ulysses S. Grant reinforced troops at Chattanooga and advanced to Orchard Knob against Confederate troops besieging the city. The next day, the Battle of Lookout Mountain was fought, driving the Confederates off the mountain. On November 25, Grants army routed the Confederates in the 