As the Chickamauga campaign began, Buckner was ordered south to Chattanooga, leaving only a single brigade in the Cumberland Gap and one other east of Knoxville. Maj. Gen. Samuel Jones replaced Buckner as commander of the department at East Tennessee. One of Burnside's cavalry brigades reached Knoxville on September 2, virtually unopposed. The following day, Burnside and his main force occupied the city, welcomed warmly by the local populace.