The Chattanooga Campaign was a series of Union operations during the autumn of 1863 that broke Confederate General Braxton Bragg's siege of the Tennessee city of Chattanooga.
Events Leading Up to the Chattanooga Campaign
On December 26, 1862, Major General William S. Rosecrans led the Union Army of the Cumberland out of Nashville 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 the Confederate Army of Tennessee.
On December 31, the two armies clashed at the Battle of Stones River (December 31, 1862–January 2, 1863) near Murfreesboro, Tennessee. The Union army prevailed and forced Bragg to retreat south toward Chattanooga.
In June, the Federals moved on the Rebels again at Tullahoma, Tennessee, forcing Bragg to withdraw his army to Chattanooga. In mid-August, Rosecrans prepared to assault Chattanooga, but a series of brilliant maneuvers on his part convinced Bragg that the city was indefensible. On September 9, Bragg abandoned Chattanooga and led the Army of Tennessee through the mountains into northern Georgia.
Although Rosecrans had achieved his aim of capturing Chattanooga, he pursued Bragg’s army into Georgia. Stung by the criticism he received for abandoning Chattanooga, Bragg resolved to win the city back. On September 19, the Army of Tennessee attacked the Union Army of the Cumberland at the bloody Battle of Chickamauga (September 19–20, 1863). Bragg’s army drove the Federals back toward Chattanooga, forcing them to occupy the defensive works previously constructed by the Rebels. Bragg seized the high ground overlooking Chattanooga (Lookout Mountain, Missionary Ridge, and Raccoon Mountain) and laid siege to the city.
Chattanooga Under Siege
From his lofty positions above the Chattanooga, Bragg could shell the city and cut off essential supplies. Bragg also severed the main rail line coming into Chattanooga, leaving Rosecrans with only a poor dirt road through mountainous terrain to supply his army. Rosecrans’ situation became a priority in Washington. The War Department dispatched Major General Joseph Hooker with 15,000 men from the Army of the Potomac to Chattanooga.
Ulysses S. Grant to the Rescue
They also created the Military Division of the Mississippi, placing Major General Ulysses S. Grant in charge of all Union armies in the western theater. On September 29, Secretary of War Edwin Stanton ordered Grant and 20,000 soldiers to leave Vicksburg, Mississippi to help lift the siege in Chattanooga. Grant immediately relieved Rosecrans of his command and placed Major General George Thomas in charge of the Army of the Cumberland. Grant himself arrived in Chattanooga on October 23 and took personal command of all forces within the city.
The Cracker Line
Upon his arrival, Grant set about establishing a new supply line going into Chattanooga. With the help of Hooker’s troops arriving from the east, the Federals captured a ferry landing on the Tennessee River and created a new supply route later known as the “Cracker Line.” The new route cut the length of the existing supply line in half.
Confederate forces under General James Longstreet tried unsuccessfully to sever the Cracker Line with an attack at Wauhatchie, Tennessee on October 29. The next day, the first supplies began arriving in Chattanooga over the new route, and conditions within the city immediately improved.
Grant Plans to Take the Offensive
While waiting for Major General William T. Sherman and the Army of the Tennessee to arrive from Vicksburg, Grant and his staff began preparing for an offensive to drive the Rebels away from Chattanooga and relieve the city.
Sherman arrived in Chattanooga on November 14, 1863, ahead of his army, and quickly endorsed the plans that Grant’s staff created. Sherman’s army began arriving at Chattanooga on November 20. Three days later, the offensive moved into action.
On November 23, about 14,000 Federal soldiers left their defensive works and overran the 600 Confederate defenders of a hill between Chattanooga and Missionary Ridge, known as Orchard Knob. The Union soldiers fortified the hill, and Orchard Knob served as Grant’s headquarters for the rest of the breakout.
Joseph Hooker Assaults Lookout Mountain
The next day, about 10,000 Union forces under the command of Major General Joseph Hooker began an assault on the Confederates holding Lookout Mountain. The Federals made steady progress in a battle that lasted all day, much of it fought in a heavy fog. When Hooker’s troops threatened to cut off any avenue of escape, Bragg ordered the evacuation of the mountain during the night. When the sun rose the next day, the Union held Lookout Mountain.
Army of the Cumberland’s Heroic Charge at Missionary Ridge
On the same day that Hooker forced the abandonment of Lookout Mountain, Sherman moved three divisions across the Tennessee River and captured a position called Goat Hill near the Confederate lines on Missionary Ridge. On November 25, Grant ordered Sherman to advance on Missionary Ridge from the north and Hooker from the south. Sherman and Hooker launched their assaults early in the morning but made little headway by afternoon. Seeing their lack of progress, Grant ordered Thomas to lead the Army of the Cumberland in an assault on the Confederate center.
The assault was initially successful, but rifle and artillery fire from the ridge above eventually tied Thomas’ men down. Still stinging from their embarrassing defeat at the Battle of Chickamauga in September, the Army of the Cumberland mounted a second heroic charge up the ridge and overran the Rebels. By 6 o’clock, the center of Bragg’s army was in full retreat and the Union held Missionary Ridge.
Braxton Bragg Retreats South
After abandoning Missionary Ridge, Bragg ordered his army to march south toward Dalton, Georgia. Sherman and Hooker pursued briefly, but Grant soon called a halt, not wanting his forces to get too far from their supply lines.
Outcome of the Chattanooga Campaign
The breakout from Chattanooga cost the Union almost 6,000 casualties, including 753 killed. The Confederates suffered about 6,600 casualties, including 361 killed. Over 4,000 of the Rebel casualties were prisoners. Following the breakout, the Union held uncontested control of Chattanooga, the “Gateway to the Lower South.” Chattanooga became an important supply center for Sherman’s Atlanta Campaign in 1864.