The Confederates now settled down to siege tactics and attempted to force the surrender of the Army of the Cumberland through starvation. By occupying Lookout Mountain and Missionary Ridge and by establishing a line between the two heights, they cut off all but the most difficult route by which supplies could be brought into the city. Within a month the Union Army in Chattanooga was in a desperate situation and was reduced to half rations. Ten thousand horses and mules died and surrender seemed inevitable. The North, however, met this crisis by a change of command and reinforcements. Troops from the Army of the Potomac in Virginia and from Grant’s Vicksburg forces in Mississippi were sent hurrying to Chattanooga, and General Grant arrived to take the overall command. The reinforcements arrived in time to save the besieged army. A new supply route was opened and was successfully defended. As a result of this timely aid, the siege of Chattanooga failed. Nevertheless, the Confederates still held their positions. In November the greatly strengthened Union Army assumed the offensive. [Illustration: _Missionary Ridge from DeLong Reservation._] _The Battle of Chattanooga_ The Battle of Chattanooga was a 3-day engagement, November 23 to 25. As planned by the Union officers, victory was to be won by a flanking movement against the Confederate right wing on the north end of Missionary Ridge. If this position were carried, Union troops in the center were to join in an effort to sweep the Confederates from their base of supplies and communications and to defeat them. The engagement, however, developed much differently. While the main force was maneuvered into position, a demonstration attack was made on a Confederate outpost at Orchard Knob, about a mile in front of Missionary Ridge. This advance movement was successfully carried out on November 23 but it warned the Confederates of danger on that right flank and prompted them to strengthen their positions. On the next day, while the maneuvering force was still getting into position, the Union officers tried another demonstration, this time to divert the Confederates on their left. Moving along the slopes of Lookout Mountain from the western side, Union troops gradually drove back the few Confederate defenders. At Cravens Farm, however, they met stubborn resistance from an entrenched line of troops. Here the fighting was most serious, the Confederates finally being dislodged and forced to retreat to a new line 400 yards beyond. At this point the fighting ended, and although the Confederates had not yet been driven from the mountain, their position was in danger. Rather than risk being cut off from the main line of forces on Missionary Ridge, the Confederate commander, General Bragg, evacuated all troops from Lookout Mountain and the valley below. When Union soldiers scaled the palisades the next morning, they found the mountain deserted.