Fought on September 17, 1862, the Battle of Antietam is often described as a "slaughter" due to the staggering number of casualties, making it the bloodiest single-day battle in American history.

Approximately 22,000 soldiers were killed, wounded, or missing in just one day of fighting. This brutal encounter took place near Sharpsburg, Maryland, and resulted in a tactical draw but a strategic victory for the Union, as it halted General Robert E. Lee’s invasion of the North. The immense loss of life highlighted the war's harsh realities and intensified calls for emancipation.