The struggle for Chattanooga reveals itself in David Greenspan’s panorama. After replacing Rosecrans as commander of the Army of the Cumberland, Thomas fortified Chattanooga (1). Bragg, holding Missionary Ridge and Lookout Mountain, commanded the supply lines to the city until troops under Thomas and Hooker opened the “cracker line” (2), a route that let supplies reach Chattanooga from the depot at Bridgeport. Grant, the new theater commander, then moved to dislodge Bragg. On November 23 Thomas took the high ground of Orchard Knob (3) in front of Missionary Ridge. The next day Hooker stormed Lookout Mountain (4) and threatened Bragg’s left while Sherman crossed the Tennessee River (5) to strike his right (6). On November 25 Grant made his major effort. When Sherman got bogged down in hard fighting on the Rebel right (7), Grant ordered Thomas to take the Confederate line at the foot of Missionary Ridge (8). Thomas’s men did—and then kept on going. Without orders, they scrambled up the steep sides of the ridge, swept across the crest (9), and completely routed Bragg’s army.