Sometime before. Gen. Shackelford had been ordered to report from upper East Tennessee at Knoxville, to take command there of all the United States cavalry, and on the approach of Longstreet, Haskin’s brigade was ordered to that place. This left Gen. Wilcox, with his new division, with some newly recruited North Carolinians, and also Foster’s division of cavalry, composed of Graham’s and Garrard’s brigades, in the country above Knoxville. The whole command in that region, though it consisted of good men, was in bad condition, for want of almost everything that was needful. Burnside, when he learned certainly that Longstreet was advancing towards him, directed Wilcox to arrange for the march of his command to Cumberland Gap, in the event telegraphic communication between him and Gen. Burnside’s headquarters should be broken. On that night, November 16, it was cut off, at the same time that the siege of Knoxville was about to begin. The United States Army under Gen. Rosecrans had been saved on the 20th of September by the firmness of Gen. Thomas. It was then shut up in Chattanooga by Gen. Bragg, who reported to Richmond that he expected its “speedy evacuation” of that place, “for want of food and forage.” Whether Bragg thought that, as he said, he held his enemy at his mercy, and therefore could weaken his own force for a distant purpose, or whether, as Gen. Grant thought probable, the movement of troops to that end was ordered by Jefferson Davis, in default of his endeavor to reconcile a serious difference between Bragg and Longstreet, a heavy force, including cavalry, was detached from Bragg’s army and sent under Longstreet to capture Burnside.[34]