In mid-December 1863 both sides in the war announced important command changes. For the Federals, on December the 9th, General John Foster replaced Ambrose Burnside in command of the Union Army of the Ohio.
Burnside, who had been criticized for not actively supporting Rosecrans at Chattanooga, had for some time desired to leave his command. For the Confederates, on the 15th Confederate General Jubal Early was assigned to the Shenandoah Valley District. And, on the following day, General Joseph Johnston was named to succeed General William Hardee as a permanent replacement for Braxton Bragg at the head of the Confederate Army of Tennessee.
Johnston’s transfer left General Leonidas Polk in command of the Confederate Army of Mississippi, of which he formally took charge on Tuesday, December 22, l863.