Following the debacle of the battle of Fredricksburg in December 1862, Burnside was replaced as commander of the Army of the Potomac by General Joseph Hooker. Having reorganized the army and improved morale, he planned an attack that would take his army to Richmond and end the war. Although outnumbered 2:1, the Confederate commander Robert E. Lee split his forces: Jubal Early was left to hold off Sedgwick's Fredericksburg attack, and Stonewall Jackson was sent with 26,000 men in a wide envelopment around Hooker's right flank. At dusk on May 2, Jackson's men crashed into the Federal right flank, and despite stiffening Federal resistance the next day, the victory at Chancellorsville was Lee's masterpiece.