The Battle of Antietam was fought on September 17, 1862, during the American Civil War. It took place near Sharpsburg, Maryland, and was one of the bloodiest single-day battles in American history, with about 22,000 soldiers killed or wounded. The battle was significant because it halted the Confederate Army led by General Robert E. Lee from advancing into the North. The outcome of the battle gave Union General George McClellan a strategic victory, although he did not pursue Lee's retreating forces. This battle also led to President Abraham Lincoln issuing the Emancipation Proclamation, which aimed to free enslaved people in the Confederate states.