Dawn approached slowly through the fog on September 17, 1862. As soldiers tried to wipe away the
dampness, cannons began to roar and sheets of flame burst forth from hundreds of rifles, opening a
twelve hour tempest that swept across the rolling farm fields in western Maryland. A clash between
North and South that changed the course of the Civil War, helped free over four million Americans,
devastated Sharpsburg, and still ranks as the bloodiest one-day battle in American history.
The Battle of Antietam was the culmination of the Maryland Campaign of 1862, the first invasion of
the North by Confederate General Robert E. Lee and the Army of Northern Virginia. In Kentucky and
Missouri, Southern armies were also advancing as the tide of war flowed north. After Lee’s dramatic
victory at the Second Battle of Manassas during the last two days of August, he wrote to Confederate
President Jefferson Davis that “we cannot afford to be idle.” Lee wanted to keep the offensive and
secure Southern independence through victory in the North; influence the fall mid-term elections;
obtain much needed supplies; move the war out of Virginia, possibly into Pennsylvania; and to liberate
Maryland, a Union state, but a slave-holding border state divided in its sympathies.
After splashing across the Potomac River and arriving in Frederick, Lee boldly divided his army to
capture the Union garrison stationed at Harpers Ferry. Gateway to the Shenandoah Valley, Harpers
Ferry was a vital location on the Confederate lines of supply and communication back to Virginia. The
12,000 Union soldiers at Harpers Ferry threatened Lee’s link south. Gen. Thomas “Stonewall” Jackson
and about half of the army were sent to capture Harpers Ferry. The rest of the Confederates moved
north and west toward South Mountain and Hagerstown, Maryland.
Back in Washington D.C., President Abraham Lincoln turned to Major General George B. McClellan
to protect the capital and respond to the invasion. McClellan quickly reorganized the demoralized
Army of the Potomac and advanced towards Lee. The armies first clashed on South Mountain where
on September 14 the Confederates tried unsuccessfully to block the Federals at three mountain passes
– Turner’s, Fox’s and Crampton’s Gaps.
Following the Confederate retreat from South Mountain, Lee considered returning to Virginia.
However, with word of Jackson’s capture of Harpers Ferry on September 15, Lee decided to make
a stand at Sharpsburg. The Confederate commander gathered his forces on the high ground west
of Antietam Creek with Gen. James Longstreet’s command holding the center and the right while
Stonewall Jackson’s men filled in on the left. The Confederate position was strengthened with the
mobility provided by the Hagerstown Turnpike that ran north and south along Lee’s line; however
there was risk with the Potomac River behind them and only one crossing back to Virginia. Lee and his
men watched the Union army gather on the east side of the Antietam.
The Battle of Antietam National Park Service
U.S. Department of the Interior
Antietam National Battlefield
P. O. Box 158
Sharpsburg, MD 21782
“…we are driven to protect our
own country by transferring the
seat of war to that of an enemy
who pursues us with a relentless
and apparently aimless hostility.”
Jefferson Davis
September 7, 1862
“The present seems to be the
most propitious time since the
commencement of the war for
the Confederate army to enter
Maryland.”
General R.E. Lee
3 September1862
