Chattanooga Campaign - Background

Background

Chattanooga was a vital rail hub (with lines going north toward Nashville and Knoxville and south toward Atlanta), and an important manufacturing center for the production of iron and coke, located on the navigable Tennessee River. In September 1863, the Union Army of the Cumberland under Maj. Gen. William S. Rosecrans executed a series of maneuvers that forced Confederate Gen. Braxton Bragg and his Army of Tennessee to abandon Chattanooga and withdraw into northern Georgia. Rosecrans pursued Bragg and the two armies collided at the Battle of Chickamauga on September 19–20. Bragg achieved a major victory when a gap was opened mistakenly in the Union line and a strong column commanded by Lt. Gen. James Longstreet drove through it and routed a good portion of the Union army. A determined defensive stand by Maj. Gen. George H. Thomas on Snodgrass Hill saved the army from total destruction, earning him the nickname "Rock of Chickamauga" and allowing time for most of Rosecrans's army to retreat to Chattanooga. Bragg did not cut off the escape routes to Chattanooga and did not organize a pursuit that might have seriously damaged the Union army before it could regroup and prepare its defenses in the city. The Union forces took advantage of previous Confederate works to erect strong defensive positions in a tight, 3-mile-long semicircle around the city.

Bragg had three alternative courses of action. He could outflank Rosecrans by crossing the Tennessee either below or above the city, assault the Union force directly in their fortifications, or starve the Federals by establishing a siege line. The flanking option was deemed to be impracticable because Bragg's army was short on ammunition, they had no pontoon for River crossing, and Longstreet's corps from Virginia had arrived at Chickamauga without wagons. A direct assault was too costly against a well fortified enemy. Receiving intelligence that Rosecrans's men had only six days of rations, Bragg chose the siege option, while attempting to accumulate sufficient logistical capability to cross the Tennessee.

However, the Union situation soon became perilous as Bragg's army besieged the city, threatening to starve the Union forces into surrender. The Confederates established themselves on Missionary Ridge and Lookout Mountain, both of which had excellent views of the city, the Tennessee River flowing through the city, and the Union's supply lines. Bragg also had little inclination to take offensive action against the Federal army because he was occupied in infighting within his own army. On September 29, Bragg relieved from command two of his subordinates who had disappointed him in the Chickamauga Campaign: Maj. Gen. Thomas C. Hindman (who had failed to destroy part of the Union army at McLemore's Cove) and Lt. Gen. Leonidas Polk (who had delayed attacking on September 20 of Chickamauga). On October 4, twelve of his most senior generals sent a petition to Confederate President Jefferson Davis, demanding that Bragg be relieved of command. Davis personally visited Chattanooga to hear the complaints. After he decided to retain Bragg in command, Bragg retaliated against some of those generals by relieving Lt. Gen. D.H. Hill and Maj. Gen. Simon B. Buckner.

Never in the history of the Army of the Cumberland had the spirit of its officers and men been more depressed. The battle of Chickamauga had not only been fought and lost, but we also lost what was more than losing the battle. We had lost confidence in our commander.

In Chattanooga, Rosecrans was stunned by the defeat of his army and became psychologically unable to take decisive action to lift the siege. President Abraham Lincoln remarked that Rosecrans seemed "confused and stunned like a duck hit on the head." Union soldiers began to feel the effect of extremely short rations and many of their horses and mules died. The only supply line that was not controlled by the Confederates was a roundabout, tortuous course nearly 60 miles long over Walden's Ridge from Bridgeport, Alabama. Heavy rains began to fall in late September, washing away long stretches of the mountain roads. On October 1, Maj. Gen. Joseph Wheeler's Confederate cavalry intercepted and severely damaged a train of 800 wagons—burning hundreds of the wagons, and shooting or sabering hundreds of mules—at the start of his October 1863 Raid through Tennessee to sever Rosecrans's supply line. Toward the end of October, Federal soldiers' rations were "four cakes of hard bread and a quarter pound of pork" every three days.

The Union high command began immediate preparations to relieve the city. Only hours after the defeat at Chickamauga, Secretary of War Edwin M. Stanton ordered Maj. Gen. Joseph Hooker to Chattanooga with 15,000 men in two corps from the Army of the Potomac in Virginia. Maj. Gen. Ulysses S. Grant was ordered to send 20,000 men under his chief subordinate Maj. Gen. William T. Sherman, from Vicksburg, Mississippi. On September 29, Stanton ordered Grant to go to Chattanooga himself, as commander of the newly created Military Division of the Mississippi, bringing all of the territory from the Appalachian Mountains to the Mississippi River (and much of the state of Arkansas) under a single commander for the first time. Grant was given the option of replacing the demoralized Rosecrans with Thomas. Although Grant did not have good personal relations with either general, he selected Thomas to command the Army of the Cumberland. Hearing an inaccurate report that Rosecrans was preparing to abandon Chattanooga, Grant telegraphed to Thomas, "Hold Chattanooga at all hazards. I will be there as soon as possible." The Rock of Chickamauga replied immediately, "We will hold the town till we starve." Grant traveled over the treacherous mountain supply line roads and arrived in Chattanooga on October 23.