Lee's greatest tactical masterpiece — outnumbered more than two to one, he divided his army twice and destroyed a Union force twice his size, then lost his irreplaceable right arm.
The Battle of Chancellorsville (April 30 – May 6, 1863) is widely considered Robert E. Lee's greatest battlefield performance. Facing Union General Hooker's 134,000-man army with only 60,000 men, Lee did what no military textbook would recommend: he divided his already outnumbered force not once but twice.
Hooker had an excellent plan — crossing above and below Lee simultaneously to trap him between two forces. But when Lee advanced aggressively on May 1, Hooker inexplicably lost his nerve and ordered his army back to defensive positions, surrendering the initiative to the smaller Confederate force.
Lee and Jackson spent the night of May 1–2 huddled together on cracker boxes in the dark, planning one of the war's boldest moves. Jackson would take 28,000 men on a 12-mile flank march through dense forest, completely hidden from Union observers, to hit the exposed Union right flank.
Jackson's attack on the evening of May 2 was devastating. The Union XI Corps was surprised while cooking dinner, their weapons stacked, and routed in minutes. Jackson's men drove through the forest in the fading light, routing an entire corps and nearly breaking the Union army in two.
That same evening, returning from a night reconnaissance, Jackson was accidentally shot three times by his own North Carolina troops who mistook his party for Union cavalry. His left arm was amputated; Lee sent word that he had lost his right arm. Eight days later, Jackson died of pneumonia.
Lee won his greatest victory, but at a cost the Confederacy could not sustain. Union casualties of 17,287 were numerically higher, but Confederate losses of 12,764 — including Jackson — represented a far higher proportion of a much smaller army. Lee never found another Jackson.