When Union Maj. Gen. Joseph Hooker crossed the Rappahannock on this date, he placed his Army of the Potomac on Confederate Gen. Robert E. Lee’s vulnerable flank. His advance would signal the beginning of the 7-day Battle of Chancellorsville.
Rather than retreat before this sizable Federal force, (130,000 Federals to Lee's 60,000) Lee opted to risk an attack against Hooker while he was still within the thick wilderness. Late the following day, Lee and and his Lt. Gen. Thomas "Stonewall" Jackson conceived one of the boldest plans of the war. Jackson, with 30,000 Confederates, would follow a circuitous route to the Union right and from there conduct an attack on that exposed flank.