JULY 1, 1863: The pivotal Battle of Gettysburg begins as Confederate forces under Robert E. Lee clash with Union troops under George Mead in the small Pennsylvania crossroads town, with both commanders quickly committing more and more forces. Both sides take heavy losses in close fighting at sites such as Little Round Top, Cemetery Hill, and the Devil’s Den, with the momentum frequently shifting to either side. On the third day Lee makes a crucial error by sending General George Pickett on a doomed charge against entrenched Union lines. His army shattered, Lee prepared for a counter-attack that never came, and later slipped away in a heavy rain. With more than 100,000 killed or wounded on both sides, Gettysburg was among the war’s bloodiest days and a turning point in the conflict, marking the end of Lee’s strategy of invading the North.