Battle of Antietam

The Battle of Antietam was a massive engagement during the American Civil War.

It took place on September 17, 1862, near Sharpsburg, Maryland. This fight was part of the larger Maryland Campaign. It was the first time a field army-level battle occurred on Union soil.

The fighting centered around Antietam Creek. This single day remains the bloodiest in American history. A total of 22,726 men were killed, wounded, or went missing.

Before the battle, Confederate General Robert E. Lee moved his Army of Northern Virginia into Maryland.

He wanted to bring the war into enemy territory. He also needed food for his soldiers from northern farms. Confederate leaders hoped a victory on Union soil would win support from foreign nations. They specifically hoped for recognition from the United Kingdom and France.

Many Confederates thought Maryland would welcome them. However, pro-Union feelings were growing in the state. Most civilians stayed inside their homes as the armies passed.

Major General George B. McClellan led the Union Army of the Potomac.

His force was much larger than Lee's. A historian named D. Scott Hartwig estimates McClellan had 72,199 men ready for combat. He also had 293 cannons available. About one-quarter of his army consisted of inexperienced, new recruits.

In contrast, Lee led about 55,000 men. Lee's army was poorly supplied and far from its logistical lines. Many Confederate soldiers used smoothbore weapons with shorter ranges. They also used many obsolete cannons compared to the modern Union guns.

One famous moment happened before the fighting started. Two Union soldiers found a copy of Lee's detailed battle plans. These plans were wrapped around three cigars. This document was called Special Order 191. It showed that Lee had divided his army. This made his forces vulnerable to being defeated one by one. McClellan waited about 18 hours before acting on this intelligence. This delay meant he could not defeat Lee decisively.

The battle began at dawn with several intense attacks.

Major General Joseph Hooker led an assault on the Confederate left flank. Fighting moved through Miller's Cornfield and around the Dunker Church.

Later, Union troops attacked a spot called the Sunken Road. They eventually pierced the Confederate center. However, the Union did not follow up on this advantage. In the afternoon, Major General Ambrose Burnside moved against the Confederate right.

His men captured a stone bridge over Antietam Creek.

The battle reached a turning point during Burnside's advance. Confederate Major General A. P. Hill arrived from Harpers Ferry. His division launched a surprise counterattack. This movement drove Burnside's troops back and ended the battle.

Although Lee was outnumbered two-to-one, he committed his entire force. McClellan sent in less than three-quarters of his army. This allowed Lee to fight the Union forces to a standstill. Both armies spent the night consolidating their lines.

While the battle was tactically inconclusive, it was a strategic Union victory.

McClellan successfully stopped Lee's invasion of the North. However, the Union suffered much heavier casualties than the Confederates. President Abraham Lincoln was unhappy with McClellan's cautious leadership. He relieved McClellan of his command in November 1862. Despite this, the battle changed the direction of the war. It gave Lincoln the political confidence to issue the Emancipation Proclamation.

This also discouraged Britain and France from supporting the Confederacy.