Once the Cracker Line broke the siege, Bragg had to choose among retreat, a direct assault, and waiting for Grant. Longstreet's two divisions were directed into East Tennessee against Ambrose Burnside at Knoxville. The move removed a substantial body of troops from the smaller Confederate army at Chattanooga. It also removed Longstreet after his mishandling of Brown's Ferry and Wauhatchie, which gave Bragg some relief from a serious command problem.
Notable Point · 1:12:25-1:15:22
Sending Longstreet to Knoxville traded troops for command relief
With the siege broken, Bragg sends Longstreet's two divisions against Burnside at Knoxville, weakening his army but removing a subordinate whose recent attacks he condemned.