Prelude to the Battle
Rosecrans Moves Toward Chattanooga
On December 26, 1862, Major General William S. Rosecrans led the Union Army of the Cumberland out of Nashville, Tennessee with orders to capture Chattanooga, Tennessee. Chattanooga was an important railroad junction that connected the upper Confederacy with the Deep South. Between Rosecrans and Chattanooga was Lieutenant General Braxton Bragg and his Confederate Army of Tennessee.
Bragg Abandons Chattanooga
The two armies clashed in a series of battles over the next nine months and Confederates consistently retreated south. On September 9, Bragg abandoned Chattanooga and led the Army of Tennessee through the mountains into northern Georgia.
Bragg Stuns Rosecrans at Chickamauga
Although Rosecrans achieved his goal of capturing Chattanooga, he pursued Bragg’s army into Georgia. Stung by criticism that he received for abandoning Chattanooga, Bragg counterattacked at the Battle of Chickamauga (September 19–20, 1863).
Bragg Invests Chattanooga
The victorious Confederates drove the Federals back toward Chattanooga, forcing them to occupy the defensive works previously constructed by the Confederates. Bragg seized the high ground overlooking Chattanooga (Lookout Mountain, Seminary Ridge, and Raccoon Mountain) and laid siege to the city.
Changes in Federal Leadership
Reacting to the Army of the Cumberland’s dire situation, Northern authorities sent 20,000 soldiers commanded by General Joseph Hooker, and 16,000 men led by Major General William T. Sherman to help lift the siege. Officials placed General Ulysses S. Grant in command of all Northern soldiers near Chattanooga and also replaced Rosecrans with General George Thomas as the commander of the Army of the Cumberland.
As reinforcements arrived in late October 1863, Grant launched an operation to ease the Army of the Cumberland’s supply problems. By October 28, Grant’s men opened a narrow supply line known as the “Cracker Line” and provisions started flowing into Chattanooga.
Longstreet Departs for Knoxville
On November 4, 1863, Bragg detached 15,000 soldiers from his army and sent them to East Tennessee under the command of Lieutenant General James Longstreet. Longstreet’s task was to dislodge Major General Ambrose Burnside and the Union Army of the Ohio from Knoxville and prevent him from reinforcing Grant at Chattanooga. Longstreet’s departure weakened Bragg’s forces investing Chattanooga.
Grant Plans to Take the Offensive
Following the opening of the Cracker Line, Grant began planning an assault on the Confederate forces. He intended to wait until Sherman’s men reached Chattanooga. Sherman’s men began arriving on November 20, but most of his force showed up later. On November 23, rumors circulated through Northern lines that the Confederate forces were retreating. Grant ordered General Thomas to reconnoiter the center of the Confederate line at the base of Missionary Ridge to determine Bragg’s intentions.
Battle of Orchard Knob
Early in the afternoon, 14,000 Northern forces under Brigadier General Thomas J. Wood easily overpowered the 634 Confederates at the Battle of Orchard Knob. Initially, Grant had directed the men to return to Northern lines, but upon seeing the ease the Union men had in securing the position, he ordered his soldiers to hold the position and to entrench.
Clash at Lookout Mountain — Battle Above the Clouds
Union forces continued their assault on the Confederate position the next day. On November 24, General Hooker’s men attacked Confederate forces on Lookout Mountain, on the Southerners’ left flank. By mid-afternoon, the Union assault had stalled, primarily because a dense fog enveloped the mountain. The thick fog prompted soldiers later to nickname the Battle of Lookout Mountain as the Battle Above the Clouds. Although Hooker’s men did not take the mountain, he correctly predicted that Southern forces would withdraw from the mountain that night.
Aftermath of the Battle
Confederate casualties at the Battle of Lookout Mountain roughly doubled Union losses. The Confederacy lost about 1,200 soldiers (killed, wounded and missing/captured) compared with 400-650 Federals (killed, wounded and missing/captured). Hooker’s triumph enabled him to assist in the Union victory at the Battle of Missionary Ridge the following day.