Battle of the Cumberland Gap ( 1863 ) The September 7 – 9 , 1863 fall of the Cumberland Gap was a victory for Union forces under the command of Ambrose Burnside during his campaign for Knoxville . The bloodless engagement cost the Confederates 2 , 300 men and control of the Cumberland Gap . Background . Major General Ambrose Burnside , commander of the Department and Army of the Ohio , began to advance against Knoxville , Tennessee . Burnside left Cincinnati , Ohio in mid - August 1863 . The direct route ran through the Confederate - held Cumberland Gap . Burnside had been delayed in earlier attempts to move out against Knoxville and thus chose not to spend the time to force a passage of the gap . Instead he detached one brigade under Colonel John F . DeCourcy to pose a threat to Brigadier General John W . Frazer ' s 2 , 300 man garrison , while the rest of the army bypassed to the south over 40 miles in rugged mountainous terrain . DeCourcy had previously led a brigade in the 1862 operations against the Cumberland Gap under George W . Morgan . Despite this , Burnside made a rapid advance on Knoxville . Many of the Confederates in eastern Tennessee had been withdrawn for the upcoming Battle of Chickamauga , leaving only two brigades under General Sam Jones ( including Frazer ' s ) . Having successfully occupied Knoxville on September 2 , Burnside could now return his attention to the Cumberland Gap . Battle . Frazer and his 2 , 300 - man garrison had little combat experience , yet they had the benefit of a strong natural defense . Frazer ' s men supplemented this by digging their own trenches . General Simon B . Buckner had given Frazer orders to hold the gap at all cost , yet when Buckner and all his troops were redeployed , no contingency had been formulated for retreat and therefore Frazer continued following his orders from Buckner to hold the gap . DeCourcy ' s brigade threatened the Confederates from the north , but his brigade alone was not enough to force Frazer out of the gap . Burnside dispatched a second brigade under Brigadier General James M . Shackelford . Shackelford approached from the south and , on September 7 , asked for Frazer ' s surrender . There were still not enough Union troops to convince Frazer to surrender . Burnside personally left Knoxville with a brigade under Colonel Samuel A . Gilbert and marched 60 miles in just over a day . On September 8 both DeCourcy and Shackelford sent messages demanding surrender , all of which were rejected . Around 10 : 00 a . m . on September 9 , Burnside sent a message to Frazer stating he now had a large enough force to carry the gap by storm . The large Union force , little combat experience and low morale ( after news of Vicksburg and Gettysburg ) all factored into Frazer ' s decision to surrender . Around 3 : 00 p . m . Frazer agreed to an unconditional surrender of all the Confederates guarding the Cumberland Gap . Between 100 - 300 men managed to escape through DeCourcy ' s lines after the surrender had taken place , but the rest of the soldiers , arms , 14 pieces of artillery and the strategic location were now in Union control . This was the last major operation against the Cumberland Gap and it would remain in Union hands for the rest of the war . Opposing Forces . Union . Department of the Ohio - Maj . Gen . Ambrose E . Burnside 29th North Carolina Infantry Regiment Company E .