Lee's bold invasion of Pennsylvania brought the war to Northern soil — and ended in the bloodiest battle ever fought in North America, shattering Confederate hopes of winning the war.
After his brilliant victory at Chancellorsville, Lee launched his second — and most ambitious — invasion of the North in June 1863. He marched 75,000 Confederate soldiers into Pennsylvania, threatening cities as far north as Harrisburg and sending civilian populations fleeing in panic.
Lee had multiple strategic goals: strip Virginia of the war's destruction during summer campaigning, gather desperately needed supplies from Pennsylvania's rich farms, and deliver a blow on Northern soil so devastating that Lincoln would be forced to negotiate peace.
The campaign's defining engagement came at a small Pennsylvania crossroads town called Gettysburg, where advance Confederate forces searching for shoes stumbled into Union cavalry on July 1. What began as a minor skirmish escalated into the largest battle ever fought in the Western Hemisphere.
Lincoln replaced General Hooker with General George Meade just three days before the battle began — an extraordinary command change on the eve of the campaign's climax. Meade had never commanded the Army of the Potomac before, yet he fought Lee to a standstill over three days.
Confederate losses at Gettysburg were catastrophic and, crucially, irreplaceable. Of roughly 75,000 Confederate soldiers engaged, over 28,000 were killed, wounded, or captured — more than a third of Lee's entire army. The Army of Northern Virginia would never fully recover its offensive punch.
On July 4 — the same day Vicksburg fell in the West — Lee began his retreat to Virginia. The twin catastrophes of Gettysburg and Vicksburg in a single 24-hour period marked the decisive turning point of the Civil War: the Confederacy had lost its best chance to win.