During the Battle of Chancellorsville in May 1863, while operating away from Longstreet's command (because Longstreet was on detached duty near Suffolk, Virginia, at the time), Anderson pressed the Union left while Lt. Gen. Thomas J. "Stonewall" Jackson attacked the right. Anderson and Maj. Gen. Lafayette McLaws left the main battle line on May 3, and struck east to check the advance of Union Maj. Gen. John Sedgwick's VI Corps that would have led into Gen. Robert E. Lee's rear. Following the death of Stonewall Jackson on May 10, Lee reorganized his army from two into three corps. Anderson was admired enough by Lee to be considered for corps command, but instead his division was assigned to the new Third Corps, commanded by now Lt. Gen A.P. Hill, who outranked Anderson and was one of the senior-most generals in the army. After reorganizing, Anderson retained most of his existing command except for Brig. Gen Lewis Armistead's brigade, which was reassigned to George Pickett's division.