In the Cumberland Gap, 2,300 inexperienced soldiers commanded by Brig. Gen. John W. Frazer had built defenses but had no orders about what to do following Buckner's withdrawal. On September 7, confronted by DeCourcy to his north and Brig. Gen. James M. Shackelford approaching from the south, Frazer refused to surrender. Burnside and an infantry brigade commanded by Col. Samuel A. Gilbert left Knoxville and marched in only 52 hours. Finally realizing that he was significantly outnumbered, Frazer surrendered on September 9.