Battle of Gettysburg (1863)

The Battle of Gettysburg stands as the most decisive engagement of the American Civil War, permanently ending the Confederate invasion of the North. Over three days in July 1863, Union forces inflicted 50,000 to 51,000 casualties—30% more than the runner-up, the Battle of Antietam—and shattered General Lee's offensive capability. The failed Pickett's Charge on July 3 cost the Confederacy 6,000 soldiers in under an hour, making it a more catastrophic defeat than the larger Battle of Chancellorsville months earlier. This battle effectively sealed the Union's ultimate victory, a fact later underscored by Lincoln's Gettysburg Address, which redefined American democratic ideals and still resonates today.