Prelude to the Battle
On June 8, 1861, Tennessee became the last Southern state to secede from the Union. The decision, however, was far from unanimous. In the eastern part of the state, voters rejected the referendum on secession by about 20,000 votes. Starting an independent secessionist movement, citizens of East Tennessee petitioned the state legislature to form a new state that would remain in the Union. The governor responded by sending military personnel to Knoxville to enforce the statewide vote for secession from the Union. Despite attempts to coerce the population, most residents of East Tennessee and Knoxville remained pro-Union throughout the American Civil War.
After the Civil War began, President Abraham Lincoln considered the liberation of East Tennessee to be of paramount importance. Beyond the moral and political duty to support the loyal citizens of that part of the Union, East Tennessee was strategically valuable. The main railway connecting the Confederate capital at Richmond, Virginia to Chattanooga, Tennessee, and on to the Deep South ran through Knoxville. In addition, East Tennessee farmers produced large amounts of food supplies that could sustain whichever side controlled the area.
Despite its strategic importance and being high on the president’s list of priorities, events in other theaters of the war delayed major Union action in East Tennessee until Major General Ambrose Burnside and his Army of the Ohio moved to occupy the area in the summer of 1863.
Burnside Advances toward Knoxville
Lincoln reassigned Burnside as commander of the Department of the Ohio on January 26, 1863, following Burnside’s brief and unsuccessful tenure leading the Army of the Potomac. Burnside arrived in Cincinnati, Ohio in March, and following some controversial confrontations with Copperheads, he turned his attention to Knoxville. Burnside left Cincinnati on June 2, 1863, and marched two corps, the 9th, and 13th, to Lexington, Kentucky.
Upon arriving in Lexington, Major General Ulysses S. Grant delayed Burnside’s plans when he ordered the 9th Corps to reinforce the Union offensive to seize the Confederate stronghold at Vicksburg, Mississippi. While awaiting the return of the 9th Corps, Burnside ordered a small combined force of cavalry and infantry to conduct raids near Knoxville, destroying railroads and communications lines. On August 6, Burnside resumed his advance from Lexington to Knoxville, planning to reunite with the 9th Corps along the way.
Burnside Bypasses the Cumberland Gap
The most direct route from Lexington to Knoxville passed through the Cumberland Gap, which Confederate soldiers commanded by Brigadier General John Frazer defended. Instead of launching a direct assault on the Rebel defenders, Burnside marched two divisions of his army over forty miles of rugged terrain around the Cumberland Gap toward Knoxville.
Burnside Occupies Knoxville
Events occurring in the Chickamauga Campaign had forced Frazer’s commander Major General Simon B. Buckner to move most of his army to southern Tennessee, leaving only a token force to defend Knoxville. When Burnside’s cavalry reached Knoxville on September 2, they faced almost no opposition. The next day, the citizens of Knoxville welcomed Burnside when he marched his army into the city.
Confederate Surrender at Cumberland Gap
After occupying Knoxville, Burnside returned his attention to the 2,300 Confederate holdouts at the Cumberland Gap who refused to surrender, despite being threatened from the north by a division Burnside had left behind. On September 7, Burnside marched a brigade sixty miles in fifty-two hours from Knoxville to the Cumberland Gap, blocking any Confederate escape to the south. After Frazer realized that Burnside had surrounded him with a larger force, he surrendered on September 9.
Aftermath of the Battle
After the battle of Cumberland Gap, except for some Rebel cavalry raids and federal efforts to clear the area, East Tennessee remained relatively quiet until November 1863 when Confederate General James Longstreet launched his Knoxville Campaign.