On this day in history, September 17, 1862, Union forces beat back a Confederate invasion of Maryland at the Battle of Antietam in the Civil War. Some 23,100 men were killed, wounded, or captured on the bloodiest day in American history.
The Battle of Antietam was the culmination of the first Confederate attempt to wage war up north after victory in the Second Battle of Bull Run, as General Robert E. Lee’s Army of Northern Virginia crossed the Potomac River into Maryland, aiming to capture Washington, D.C.
Lee divided his forces, sending General Thomas “Stonewall” Jackson’s army south to capture the Union garrison at Harpers Ferry and General James Longstreet’s corps westward. Lincoln put Major General George McClellan in charge of the troops defending the capital from invasion.
McClellan’s Army of the Potomac, which outnumbered Lee’s Confederate forces two to one, clashed with the enemy on September 14, forcing its retreat near South Mountain. In fact, McClellan had acquired a copy of Lee’s orders, left behind at a campsite, and knew of his plan.
Battle Begins at Dawn
Lee considered turning back toward Virginia, but news of Jackson’s capture of Harper’s Ferry reached him on September 15, convincing him to make a stand against the Union forces across Antietam Creek, with the river at his back, near Sharpsburg, Maryland.
Longstreet held the right of the line and Jackson’s troops the left. McClellan’s strategy was to strike at Lee’s left, then the right, and finally move forward in the center, with the advance of three forces commanded by Generals Joseph Hooker, Joseph Mansfield, and Edwin Sumner.
The fighting that began in the foggy dawn on September 17 swept back and forth for eight hours through Miller’s cornfield, around the Dunker Church, and the West Woods, as the rebels were pushed back against the Sunken Road but not beaten. “No tongue can tell, no mind conceive, no pen portray the horrible sights I witnessed this morning,” wrote Captain John Taggert.
Bloody Lane
The Sunken Road, an old country lane separating two farms, was the site of the turning point in the battle and has come to be known as Bloody Lane. “We were in the very maelstrom of the battle,” remembered Lt. Frederick Hitchcock. “Men were falling every moment. The horrible noise was incessant and almost deafening.”
McClellan aimed to follow his forward movement with a charge by General Ambrose Burnside on the Confederate right. When Hooker, Mansfield, and Sumner attacked, each was beaten, but then came Burnside’s assault on the other flank.
On the Confederate side, Longstreet’s line had been too weakened to reinforce Jackson. As a result, Burnside made progress but, when fully engaged in fighting, was met with a counterattack from Lt. General A.P. Hill’s cavalry troops returning from Harper’s Ferry.
Burnside’s last major assault was driven back to the bridge (that now bears his name) by which he had crossed the creek, and darkness ended the fierce fighting. On September 18, despite skirmishes, McClellan did not renew his attack. Lee retreated across the Potomac the next day.
The Dead Lying in Heaps
About 50,000 Union soldiers, with 20,000 in reserve and 40,000 Confederates, engaged in the battle. Union casualties totaled 12,400, including 2,108 killed, 9,540 wounded, and 753 captured or missing. The Army of Northern Virginia lost 25 percent of its men, or 10,300, including 1,546 killed, 7,752 wounded, and 1,018 captured or missing.
Lincoln criticized McClellan for allowing Lee’s forces to retreat to Virginia, while news of the carnage–23,100 of the soldiers engaged and nearly 4,000 dead–spread across the nation after newspapers published Alexander Gardner’s shocking, historic photographs of the battlefield.
“I have heard of ‘the dead lying in heaps’ but never saw it till this battle,” wrote Captain Emory Upton. “Whole ranks fell together.” Twice as many men had died in one day as in the War of 1812, the Mexican War and the Spanish-American War combined. And the aura of the inevitability and invincibility of Southern independence was gone forever.
Due to the crippling casualties, Antietam was a tactical draw; but it was widely regarded as a strategic Union victory since it stopped Lee’s northern invasion, providing the positive news that Abraham Lincoln needed to issue the Emancipation Proclamation, the historic document that transformed the Civil War into an armed struggle for the abolition of slavery.
Antietam National Battlefield
Antietam National Battlefield, designated by an act of Congress on August 30, 1890, and the surrounding area is a must-visit for Civil War buffs. It retains the rural character typical of Maryland at the time and receives about 280,000 visitors every year.
![Cannon at Antietam National Battlefield](https://www.blackhistorynh.com/wp-content/uploads/2024/07/Cannon-at-Antietam-National-Battlefield-1024x512.jpg)
Run by the National Park Service, it lies 10 miles south of Interstate 70, off Exit 29, close to Washington and Baltimore. Tourists seeking a more scenic route should take the National Road from Frederick through Middletown and Boonsboro. Follow Maryland Route 34 west from Boonsboro to reach Sharpsburg and the battlefield.
The park’s visitor center features two films that explain the first major battle that took place on Union soil. There is also a self-guided auto tour that follows the battlefield from north to south. The visitor center includes a museum and gift shop that sells many books on the Civil War.
Bloody Lane, Burnside Bridge, and the Dunker Church are the highlights of the battlefield at Antietam. And the Witness Tree, next to Burnside Bridge, that was there during the decisive, bloody battle 150 years ago still stands today.
“On Wednesday morning, September 17, the sun rose in a cloudless sky,” wrote The New York Times, “and all nature seemed to smile as if the world were filled with the elect of God. But its splendors were soon dimmed with the smoke rising from the battlefield.”