Maryland: Antietam Summary

  • Last updated on November 10, 2022

The bloodiest one-day battle of the Civil War took place in the fields and woods between the town of Sharpsburg, Maryland, and Antietam Creek. The Battle of Antietam (called the Battle of Sharpsburg by the Confederacy) resulted in more than twenty-three thousand casualties.

Site Office

Antietam National Battlefield and Cemetery

National Park Service

Box 158

Sharpsburg, MD 21782

ph.: (301) 432-5124

Web site: www.nps.gov/anti/

At the start of the Civil War, the acreage between Antietam Creek and the town of Sharpsburg consisted of farm fields and woods. Several farmhouses dotted the landscape, and a Dunker church stood about one mile north of town. At the commencement of hostilities between the North and South, Maryland had declared itself neutral. It was a slave state that had remained loyal to the Union by refusing to secede from the United States as other Southern slave states had done. Maryland’s neutrality was violated in September, 1862, when forty thousand Confederate troops commanded by General Robert E. Lee marched north from Virginia across the Maryland border. As Lee’s Army of Northern Virginia marched north, the Army of the Potomac, eighty-seven thousand federal troops under the command of General George B. McClellan, moved from Washington, D.C., into Maryland to check the Confederate advance. The two armies engaged in the woods and fields east of Sharpsburg in one of the major battles of the Civil War. The site of that fierce battle is preserved as the Antietam National Battlefield and Cemetery.

Lee’s Maryland Campaign

In early September of 1862, President Jefferson Davis of the Confederacy and General Lee, encouraged by several recent stunning victories against Northern troops on Virginia soil, launched a bold plan to invade the North. Lee’s goal would be to march through Maryland into Pennsylvania and capture the city of Harrisburg, an important railroad link between the large eastern cities and Chicago. Davis and Lee assumed that a large rebel force on Northern soil would cause the United States citizenry to panic and pressure the federal government to recognize the Confederacy’s independence and end the war. When Lee began his march into Maryland, however, President Abraham Lincoln assumed that Lee’s goal was to invade Washington, D.C. He urgently ordered General McClellan to position his large army between the capital and Lee’s troops. As Lee approached Maryland he divided his troops, sending almost half his men under Major General Thomas “Stonewall” Jackson to capture a lightly guarded federal arms arsenal at Harpers Ferry, Virginia.

On September 13, McClellan became aware of Lee’s plan. In a field near Frederick, Maryland, a Union corporal had found three cigars wrapped in a piece of paper containing Lee’s orders. McClellan quickly pushed his men westward toward Lee. On September 14, Yankee and rebel troops skirmished at three passes in South Mountain. The next day, Lee, sensing a major confrontation, moved his men to ground that would be easy to defend–the crest of a three-mile ridge just east of Sharpsburg. In front of Lee’s army was Antietam Creek, and McClellan began to form his lines east of the creek facing Lee’s army.

The Battle of Antietam

Had McClellan attacked Lee on September 15, he might have crushed Lee’s army. Lee had barely twenty thousand men–the rest were at Harpers Ferry–facing McClellan’s army of eighty-seven thousand. In earlier campaigns, however, McClellan had shown himself to be a cautious general who consistently overestimated the strength of his enemy’s army. He spent two days positioning his troops before attacking, a delay that allowed the bulk of Stonewall Jackson’s army to depart from Harpers Ferry, which the rebels had captured, and join Lee at Sharpsburg.

On the morning of September 17, McClellan gave the order to attack. Before dawn, a Union artillery barrage commenced on Lee’s left flank, posted at the Dunker church north of Sharpsburg and anchored by Jackson. At first light, Union infantry under the command of Major General Joseph Hooker advanced on Jackson’s men, pushing them backward and almost turning the flank. Lee sent Jackson reinforcements, and his line held. A fierce battle between Hooker’s and Jackson’s forces developed in a cornfield. The five-foot-tall cornstalks were cut down by musket and cannon shot, and thousands of soldiers fell.

At around 9:30 a.m., McClellan attacked the center of the Confederate line. Rebel troops there under the command of Colonel John B. Gordon had positioned themselves in a sunken road, and they opened fire on Yankee infantry charging across an open field, inflicting heavy casualties. For four hours, waves of Yankee troops attacked the sunken road but were repulsed by determined rebels. Finally, men from a New York regiment moved to some higher ground where they could shoot down at the Confederates holding the sunken road. Rebel soldiers began falling in great numbers, and the sunken road–later called Bloody Lane–filled with dead bodies. Finally, the Confederates retreated, but McClellan failed to press the attack.

Just after Yankee troops attacked Lee’s center, Union regiments under the command of Major General Ambrose Burnside attacked the Confederate right flank. There, fewer than five hundred Georgia infantrymen were dug in on a ridge overlooking a stone bridge that crossed Antietam Creek. Four times Burnside’s men assaulted the bridge, but the Georgians held them off. Finally, after three hours of furious fighting, Burnside’s troops crossed the bridge and routed the rebels, sending them on a hasty retreat toward the town of Sharpsburg. Burnside requested reinforcements to press the attack, but the cautious McClellan held back.

Lee’s army was near destruction. Jackson was barely holding out on the Confederate left flank. Lee’s center had broken, and Burnside had smashed the rebel right flank. McClellan, however, remained cautious and refused to send his reserves into the battle. At around 1:00 p.m., McClellan ceased his attack to re-form his lines. For almost two hours, Lee’s men had a reprieve from the fierce Yankee assaults.

At around 3:00 p.m. the federals renewed the attack. Within an hour, however, Lee received desperately needed reinforcements. Three thousand Confederate infantry–a division under the command of Lieutenant General A. P. Hill that had been left behind to hold Harpers Ferry–arrived at Sharpsburg after a rapid seventeen-mile march. Hill’s troops attacked Burnside immediately, checking the federal advance on Lee’s right. The rebels drove Burnside’s Yankees back to the bridge that they had taken a few hours earlier, and the Yankee troops established a defensive position. McClellan, fearing that he was outnumbered, called off the attack. The battle died down as dusk fell.

The casualties were staggering. September 17, 1862, was the bloodiest day of the Civil War. Federal casualties–defined as killed, wounded, captured, or missing in action–amounted to 12,410 men. The Confederates lost 10,700, more than a quarter of Lee’s army. Eight thousand men had been killed or wounded in the early-morning battle in the cornfield. Another six thousand fell in and around the sunken road. Whole regiments had been obliterated. In several minutes of fierce fighting, the Twelfth Massachusetts Regiment lost 224 of 334 men. As the sun set on the Antietam battlefield, thousands of men lay wounded and dead in the fields and woods outside Sharpsburg. Houses in the town that had not been hit by stray shells were turned into makeshift field hospitals, where overtaxed surgeons worked to save the wounded.

Citizens of both the North and the South were aghast at the slaughter at Antietam Creek. A battle with similar casualties had never before been fought on American soil. Two weeks after the battle, the photographer Mathew Brady opened an exhibition titled “The Dead of Antietam” at his New York gallery. One reviewer commented that Brady, via his gripping battlefield photographs, had virtually laid the dead “in our door-yards and along [our] streets.”

The Battle’s Aftermath

On September 18, Lee, ever eager for a battle, reluctantly ordered a retreat. His army had suffered too many casualties to fight another day. He moved southward, back into Virginia. When Lee retreated, McClellan claimed a victory. He had stopped Lee’s invasion of the North.

President Lincoln, however, did not view the Battle of Antietam as a total victory. He had wanted McClellan to destroy Lee’s army. He had urged McClellan to block Lee’s retreat; Lincoln did not want to give Lee the opportunity to regroup and fight again. Two weeks after the battle, Lincoln pressed McClellan to move against Lee’s depleted army, now encamped in Virginia, but McClellan claimed that his army’s horses were too tired. A month later, Lincoln relieved McClellan of command of the Army of the Potomac, and McClellan retired to his home in New Jersey. Lee continued to fight for another two and a half years.

Though he was not completely satisfied with the outcome at Antietam, Lincoln used the battle politically. Since the beginning of the war, abolitionists in Congress had urged Lincoln to emancipate the slaves in the states that had seceded from the Union. Lincoln had been reluctant to free the slaves because he had consistently asserted that the war between North and South was a conflict over secession, not over slavery. By the summer of 1862, however, Lincoln had come to realize the necessity of freeing the slaves, but he wanted to wait for a Northern victory on the battlefield before taking any action. Before the Battle of Antietam, Lincoln had prayed that McClellan’s army would stop Lee’s invasion of the North. Lincoln had told members of his cabinet that he would view a Union victory as a sign from God that the slaves should be freed.

On September 22, five days after the great battle at Antietam Creek, Lincoln issued a Preliminary Emancipation Proclamation, announcing that he would free all slaves in the states in rebellion on January 1, 1863, if those states did not return to the Union. No Southern state rejoined the Union, and on January 1 Lincoln issued the Emancipation Proclamation.

Visiting Antietam National Battlefield

The National Park Service administers the Antietam National Battlefield, which is open to visitors daily except on Thanksgiving, Christmas, and New Year’s Day. Signs on Maryland Route 65 direct motorists to the visitors’ center, which houses a small museum containing photographs, uniforms, weapons, flags, and other relics from the battle. An audiovisual program shown at the visitors’ center provides an overview of the battle.

From the visitors’ center, tourists can take an auto or bicycle tour of the Antietam battlefield over a paved road. Markers are set at key points–the Dunker Church (a replica of the original, which was destroyed by a storm in 1921), the cornfield, Bloody Lane, and Burnside’s Bridge. The tour takes about two hours.

The area around Antietam battlefield remains relatively undeveloped. Woods and farm fields still dominate the landscape east of Sharpsburg, giving visitors the illusion that they have stepped back into the mid-nineteenth century when the bloodiest one-day battle of the Civil War took place.

For Further Information
  • Long, E. B. The Civil War Day by Day: An Almanac. Garden City, N.Y.: Doubleday, 1971. A detailed guide of military operations during the Civil War.
  • McPherson, James M. Battle Cry of Freedom: The Civil War Era. New York: Oxford University Press, 1983. An excellent single-volume study of the Civil War.
  • Oates, Stephen B. The Whirlwind of War: Voices of the Storm, 1861-1865. New York: HarperCollins, 1998. Oates uses first-person narrators–Lincoln, Lee, Davis, and others–to tell the story of the Civil War.
  • Sears, Stephen. Landscape Turned Red: The Battle of Antietam. New York: Warner Books, 1983. A detailed book-length analysis of the battle.
  • Ward, Geoffrey C., Ric Burns, and Ken Burns. The Civil War. Alfred A. Knopf, 1990. This illustrated history of the Civil War complements Ken Burns’s award-winning documentary film.
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