The Battle of Antietam occurred in 1862, specifically on September 17.

This pivotal battle was part of the American Civil War and is noted for being the bloodiest single-day battle in U.S. history, with around 22,000 soldiers killed or wounded. Fought near Sharpsburg, Maryland, the clash was a critical turning point in the war, as it halted General Robert E. Lee's invasion of the North. The outcome provided President Abraham Lincoln the opportunity to issue the Emancipation Proclamation, which aimed to free enslaved people in the Confederate states, redefining the war's purpose.