On September 17, 1862, the battle of Antietam (or Battle of Sharpsburg) took place. It was the first major armed confrontation of the American Civil War that occurred in northern territory and is the bloodiest in the history of the United States that was fought in a single day, with almost 23,000 casualties.
After pursuing Confederate General Lee in Maryland, Major General of the Union Army McClellan attacked Lee’s army that had established defensive positions behind the Antietam stream. The attacks and counterattacks extended and finally the Union managed to penetrate through the center of the Confederate Army. Despite the numerical superiority of the Union, McClellan’s attacks failed to concentrate troops, allowing Lee to turn his troops inside his ranks to face each attack. The battle didn’t had a conclusive result in tactical terms, however since the tactical victory of the Union was enough to give President Lincoln the security to announce his Proclamation of Emancipation.
original post published by DENIX on their website