An Overview of the 1862 Maryland Campaign and the Battle of Antietam.

The Campaign

On September 4, 1862, Robert E. Lee put into motion the series of events that led to the Battle of Antietam by marching his Army of Northern Virginia across the Potomac River into Maryland. Lee had sound reasons for moving north. If the Confederates could pull out a victory in the border state, it might influence Northern voters to elect peace candidates in the upcoming fall congressional elections and encourage Great Britain to ally formally with the Confederates. Lee also wanted to take the burden of war out of Virginia during the harvest and encourage pro-Southern support in Maryland.

In the North, things were chaotic. Major General John Pope’s Union Army of Virginia had been defeated at Second Bull Run late in August. Meanwhile, the Army of the Potomac was still returning from the Peninsula campaign and disembarking from boats in the Washington area. Union President Abraham Lincoln gave Maj. Gen. George McClellan overall command of the mess. “Little Mac” swiftly consolidated Pope’s men into the Army of the Potomac and moved out to track down Lee while at the same time protecting Washington.

With most of his cavalry still on transports, McClellan remained unaware of Lee’s position or intent until September 13, when Union soldiers found Lee’s Special Orders No. 191 near Frederick, Md. The orders showed that the army of Northern Virginia was spread out from Hagerstown, Md. to Harpers Ferry, Va.

McClellan quickly shifted his men to the west. The Confederates tried to block the Federals at Turner’s, Fox’s and Crampton’s gaps on South Mountain on September 14. They were successful—for a time. Lee had to order his men off the mountain and considered ending the campaign and heading back into Virginia. He learned, however, that “Stonewall” Jackson had captured Harpers Ferry on September 15. Encouraged by Jackson’s success, Lee concentrated his forces on the high ground west of Antietam Creek to force a showdown with Little Mac.

That showdown raged on September 17, and when it was over some 23,000 men had become casualties. On the 19th Lee retreated into Virginia, and the campaign was over.

Seizing on Lee’s retreat as a victory, Lincoln announced his intent to issue the Emancipation Proclamation in January 1863. While the document technically did not free slaves, it did call for the recruitment of black men into the Army and announced to the world that dealing with slavery was now an official part of the Northern war effort.

Strongly antislavery Great Britain no longer could consider openly opposing the Union—and England would not officially recognize the Confederacy. The gray wave that had swept over the Potomac receded, and though it flowed north again in July 1863, the true high tide of the Confederacy had ebbed in September 1862.

The Battle

With their backs to the Potomac River, the Confederates desperately fought off 12 hours of Union attacks. The rolling terrain near Sharpsburg contributed to the butcher’s bill of 23,000 casualties. Artillerymen on both sides sighted their cannons along ridgelines, blasting infantry to pieces as soon as it appeared. Many veterans referred to Antietam as “Artillery Hell.”

Dawn to 9 a.m. The Union I Corps attacked out of the North Woods, followed by the Federal XII Corps driving from the East Woods. Much of the vicious fighting between those Yankees and men of “Stonewall” Jackson’s regiments took place in the notorious Cornfield. When this phase of the fighting ended, 8,000 men were casualties.

9 a.m. to Noon Carnage continued in the center of the battlefield when the Federal II Corps first attacked toward the West Woods and tiny Dunker Church (circled), then charged on Lt. Gen. James Longstreet’s soldiers in the Sunken Road (highlighted). The Confederate line held in the West Woods but broke at the Sunken Road, although the Rebels managed to hold onto Sharpsburg.

10 a.m. to 5:30 p.m. After hours of trying, Union soldiers fought their way across Antietam Creek on the Rohrbach, or Burnside’s, Bridge. The Yankees then drove on Sharpsburg, but a Rebel counterattack by Maj. Gen. A.P. Hill’s men, just up from Harpers Ferry, hammered the advance and threw back the Federals, ending the fighting. Both sides held their positions until the 19th, when Lee retreated across the Potomac to Virginia.

Maj. Gen. George B. McClellan, commander of the Army of the Potomac, was headquartered at the Pry House during the battle. Although the site seems far from the fighting, McClellan was able to view much of the battlefield.

General Robert E. Lee set up his headquarters west of Sharpsburg. He could see little of the battlefield and therefore spent most of September 17 closer to the action.


Originally published in the September 2007 issue of America’s Civil War. To subscribe, click here.