The Battle of Antietam, fought on September 17, 1862, is known for being the bloodiest single-day battle in American history.

Taking place near Sharpsburg, Maryland, the conflict involved intense combat between Union and Confederate forces, resulting in approximately 22,000 casualties. The Union Army, led by General George McClellan, clashed with General Robert E. Lee's Confederate forces in a fierce struggle that ended inconclusively. Despite its tactical ambiguity, the Union's ability to halt Lee's advance into the North was a strategic victory, prompting President Abraham Lincoln to issue the Emancipation Proclamation shortly afterward.