On April 27, 1863, Maj. Gen. Joseph Hooker launched a turning movement designed to pry Robert E. Lee's Army of Northern Virginia out of its lines at Fredericksburg. The maneuver was successful and by April 30, elements of Hooker's Army of the Potomac had reached the crossroads of Chancellorsville, nine miles in Lee's rear. Outnumbering Lee two to one, Hooker stood poised to strike a fatal blow to the Confederates. Apprised of Hooker's march, Lee left a covering force at Fredericksburg and marched west. Fighting erupted on May 1 with the Federals ultimately retiring back to Chancellorsville. Now with the initiative, Lee would divide his army again and send Lt. Gen. Thomas J. "Stonewall" Jackson on a march to strike Hooker's right flank. The following evening, Jackson's men assailed Maj. Gen. Oliver O. Howard's XI Corps and caved in the Union line, but Jackson was wounded by friendly fire and died eight days later. Lee renewed his attack early on May 3 and dislodged Hooker from Chancellorsville. At the height of victory, Lee was forced to divide his army a third time to confront Maj. Gen. John Sedgwick's VI Corps which had broken through at Fredericksburg. The Confederates brought Sedgwick's advance to a standstill at Salem Church. Stalled on two fronts, Hooker decided to retreat and abandon his campaign on the night of May 5. The battle, considered Lee’s greatest victory, inspired him to launch a second invasion of the North.