After the Confederate victory at Chickamauga in September 1863 and the siege of Chattanooga, General Braxton Bragg turned to East Tennessee, where General Ambrose F. Burnside had occupied Knoxville after Confederate forces abandoned the city in late August. Confederate advances from the south and northeast overran Union cavalry outposts at Philadelphia and Rogersville, and on November 5 General James Longstreet began moving north from Chattanooga with veteran infantry divisions from the Army of Northern Virginia, cavalry under General Joe Wheeler, and artillery under Colonel Edward Porter Alexander and Major Austin Leyden, later reinforced by additional infantry and cavalry. On November 13 Longstreet divided his command at Sweetwater, sending Wheeler toward Knoxville’s southern heights while the main infantry and artillery force crossed the Tennessee River at Huff’s Ferry and advanced toward the city. Burnside’s army, protected by a defensive network of sixteen forts and battery positions laid out by Captain Orlando M. Poe, resisted the approach in actions at Stock Creek, Huff’s Ferry, Loudon, Lenoir Station, Campbell’s Station, and near Fort Dickerson and Fort Sanders. Fighting continued around Knoxville through late November, including actions along the Clinton Road, at Armstrong’s Hill, and a costly failed charge by the 2nd Michigan Infantry. On November 29, in a final effort to break the Union defenses, Longstreet ordered a dawn assault on Fort Sanders; after a brief bombardment, Confederate infantry attacked but were stopped by felled trees, telegraph wire, a deep ditch, an icy parapet, artillery, and about 480 Union defenders, suffering 813 casualties in about twenty minutes while the Federals lost 13. Soon after the failed assault, Longstreet learned that Bragg had been defeated at Missionary Ridge, and with Union relief columns under General William Tecumseh Sherman moving toward Knoxville, he held his lines until December 4 before withdrawing to Russellville for the winter. Burnside’s tenacious defense kept Knoxville in Union hands, and the city was not seriously threatened by Confederate forces again during the war.