Adam Badeau, Military history of Ulysses S. Grant from April 1861 to April 1865. Volume 1

On the 1st of December, Grant's dispatch to Burnside, which had been intended to fall into Longstreet's hands, was captured by the rebel scouts, and the enemy thus got information of the advance of Sherman. Longstreet himself was now cut off from all supplies, and driven to subsist off the country. The rebel command at Loudon was at once ordered to fall back on Knoxville.

On the 2d, Burnside got information of Sherman's approach; and, the same day, Longstreet determined to abandon the siege, and retreat in the direction of Virginia; his trains were put in motion on the 3d, to cross the Holston, at Strawberry plains; and, on the night of the 4th, the troops withdrew from the west side of Knoxville, and marched around to the east side, where they took up a line of march along the north bank of the Holston. This movement was unmolested by Burnside, and was made in remarkably good order.

Sherman, meanwhile, had repaired the bridge at Morgantown, and marched to Marysville; Howard constructing a bridge out of the rebel wagons left at Loudon, over which he crossed his men. On the 5th, all the heads of columns communicated, at Marysville, where Sherman received word from Burnside that Longstreet had raised the siege, and was in full retreat to Virginia. Sherman had previously sent the following note to Burnside, who was his senior: ‘Marysville, December 5, 1863. I am here, and can bring twenty-five thousand men into Knoxville to-morrow; ’