Confederate troops probing for supplies stumbled into Union cavalry west of Gettysburg, triggering an unplanned battle that grew into the largest ever fought in North America. Over three days roughly 165,000 men clashed; by July 3 Pickett's Charge had failed and Robert E. Lee's invasion of the North was broken, turning the war's momentum decisively toward the Union.
General Henry Heth's Confederate division marched toward Gettysburg on July 1 chasing rumors of a shoe supply, not expecting a fight. Instead they ran into Union cavalry under John Buford, whose stubborn delaying action on Seminary Ridge bought crucial hours for Union infantry to arrive. By afternoon, the battle had swollen into a full engagement, with Confederate forces pushing Union troops back through the town of Gettysburg itself.
The fighting that followed over the next two days, culminating in Pickett's disastrous charge on July 3, produced over 51,000 casualties combined. Lee retreated to Virginia and never again mounted a major offensive into Union territory. Four months later, Abraham Lincoln would stand on this same ground to deliver the Gettysburg Address, redefining the war's purpose in 272 words.
Key people: Robert E. Lee, George Meade, John Buford, Henry Heth