Civil War · Maryland
Antietam Battlefield
Burnside Bridge over Antietam Creek. — Frank Kovalchek
Why Antietam Battlefield Matters
Antietam was the bloodiest single day in American history. On September 17, 1862, near Sharpsburg, Maryland, the armies of Robert E. Lee and George B. McClellan fought a battle that left roughly 22,700 men killed, wounded, or missing in a single day. Though tactically inconclusive, it halted Lee's first invasion of the North — and the strategic victory gave President Lincoln the moment he needed to issue the preliminary Emancipation Proclamation, transforming the Civil War into a struggle to end slavery.
By the Numbers
The Battle
- Date
- September 17, 1862
- Also called
- The Battle of Sharpsburg
- Casualties
- ~22,700 in one day — the bloodiest in U.S. history
- Commanders
- Lee (CSA) vs. McClellan (USA)
Key sites
- On the field
- The Cornfield, Bloody Lane, Burnside's Bridge
Consequence
- Led to
- The preliminary Emancipation Proclamation
Today
- Operator
- National Park Service
Timeline
- 1862Lee invades Maryland in early September, his first move North.
- 1862Union soldiers find a lost copy of Lee's battle plans.
- 1862The Battle of Antietam is fought on September 17.
- 1862~22,700 casualties make it the bloodiest day in U.S. history.
- 1862Lincoln issues the preliminary Emancipation Proclamation on September 22.
- 1890Congress establishes Antietam National Battlefield.
Complete History
In September 1862, buoyed by victories in Virginia, General Robert E. Lee led his Army of Northern Virginia across the Potomac into Maryland, hoping a triumph on Northern soil would win foreign recognition for the Confederacy and sway Northern opinion. Union General George B. McClellan moved to intercept him, aided by a remarkable stroke of luck: a copy of Lee's battle plans, found wrapped around cigars, fell into Union hands.
The armies collided along Antietam Creek near Sharpsburg on September 17, 1862. The fighting raged from dawn across a cornfield, a sunken farm road, and a stone bridge over the creek, in some of the most concentrated carnage of the war. By nightfall about 22,700 men were casualties — killed, wounded, or missing — making it the bloodiest single day the nation has ever known. The battle itself was tactically a draw.
But strategically it was a Union victory: Lee withdrew back across the Potomac, his invasion broken. That outcome gave Abraham Lincoln the moment he had been waiting for, and on September 22, 1862, he issued the preliminary Emancipation Proclamation, declaring that enslaved people in the rebelling states would be freed. Antietam thus helped redefine the war's purpose and discouraged Britain and France from recognizing the Confederacy. The field is preserved today as Antietam National Battlefield.
Historic Images
Interesting Facts
- The Battle of Antietam, on September 17, 1862, was the bloodiest single day in American history, with about 22,700 casualties.
- It ended Robert E. Lee's first invasion of the North, forcing his army to withdraw back into Virginia.
- The Union victory gave President Lincoln the opening to issue the preliminary Emancipation Proclamation five days later.
- Before the battle, Union soldiers famously found a lost copy of Lee's orders wrapped around three cigars.
- Landmarks like the Cornfield, the Sunken Road ('Bloody Lane'), and Burnside's Bridge saw some of the war's most concentrated fighting.
Visiting Today
- Hours
- The battlefield grounds and visitor center are open daily except some winter holidays, with hours set by the National Park Service. Check ahead for current times.
- Admission
- An entrance fee is charged, valid for several days; National Park passes are accepted.
- Best time to visit
- Spring and fall offer the best weather; the battle's anniversary in mid-September brings commemorations, and an annual evening illumination honors the casualties.
- Nearby
- The town of Sharpsburg, Harpers Ferry, and the C&O Canal along the Potomac.
Follow the self-guided driving tour to key sites like the Cornfield, Bloody Lane, and Burnside's Bridge, and start at the visitor center for an orientation film that makes the day's events easier to follow.
Frequently Asked Questions
Why is Antietam significant?
It was the bloodiest single day in American history and ended Lee's first invasion of the North. The Union victory allowed President Lincoln to issue the preliminary Emancipation Proclamation.
How many people died at Antietam?
The battle produced about 22,700 casualties — killed, wounded, and missing — in one day, with roughly 3,600 killed. It remains the deadliest single day in U.S. history.
Who won the Battle of Antietam?
The battle was tactically inconclusive, but it counted as a strategic Union victory because Lee's army was forced to retreat back to Virginia, ending his invasion of the North.
Can you visit Antietam Battlefield?
Yes. Antietam National Battlefield near Sharpsburg, Maryland, preserves the field with a visitor center, a driving tour, and landmarks like Burnside's Bridge and the Sunken Road.
