Confederate Gen. Robert E. Lee had begun the campaign with high hopes inspired by his recent victory at the Second Battle of Bull Run. The Confederacy seemed to be ahead in the war; a New York Tribune bureau chief wrote, "For the first time I believe it possible...that Washington may be taken." If Lee could win another victory against the North, especially on Northern soil, England and France might issue a joint manifesto recognizing the Confederacy as a separate country. Foreign meddling could mean the end of the United States.
In Maryland, Lee decided to divide his Army, sending 22,000 troops with Gen. Thomas Jonathan "Stonewall" Jackson to attack the federal garrison at Harpers Ferry and seize the provisions and weapons his soldiers so desperately needed. After taking the Union garrison, Jackson's troops were to rejoin Lee and his remaining 18,000 men in Hagerstown, from which Lee intended to launch an invasion of Harrisburg, Pa.—an important railroad center for the Union.
But one of Lee's men made a grave mistake: He left a copy of the general's orders for the campaign on a Maryland farm field. The newly arrived Union soldiers found the orders, wrapped around three cigars inside an envelope, and sent them to Gen. George McClellan, commander of the Army of the Potomac, who exclaimed, "Here is a paper with which if I cannot whip ‘Bobbie Lee,' I will be willing to go home!"
But the notoriously cautious McClellan squandered much of his good fortune by doing nothing for 18 hours; he believed he was vastly outnumbered, although the reverse was true. On Sept. 15, McClellan slowly assembled 85,000 troops on the east bank of Antietam Creek and paused to make battle plans. On that day only 18,000 of Lee's men were available to fight the vast Union forces. He positioned them on a ridge east of Sharpsburg, right across Antietam Creek. If McClellan had attacked, he could have wiped out Lee's army—and perhaps even ended the war. McClellan hesitated, giving Lee time to reassemble his divided troops. When the Union troops did engage the Confederates, their attacks allowed Lee to shift his outnumbered men from place to place in time to repel them.
McClellan never used more than 20,000 men at a time during the entire day of fighting, keeping another 20,000 of his soldiers in reserve; they never fired a shot in battle.
Given the chaotic Union attacks, the battle of Antietam was more like three battles. The first assault started at 6 a.m. as Maj. Gen. Joseph "Fighting Joe" Hooker led his men across a cornfield toward Confederate forces near the Dunkers' church. After both sides fired, Hooker claimed, "Every stalk of corn in the greater part of the field was cut as closely as could have been done with a knife and the slain lay in rows precisely as they had stood in their ranks a few moments before." By 10 a.m., 8,000 dead or wounded soldiers littered the cornfield.
The charge of Iron Brigade near the Dunker Church. Original painting by Thure de Thulstrup. Source: Old Print Shop, New York City.
Meanwhile, on a second battlefront, the center of Lee's line held off Union attackers from a sunken country road. As waves of Union soldiers attempted to advance, they were mowed down by entrenched Confederate troops.
A Fateful Turn. Original painting by Captain James Hope - 1862, Bloody Lane. Source: National Park Service.
But the sunken road changed from an advantage to a trap when Union soldiers achieved a position from which they could shoot down on the Confederate defenders. "We were shooting them like sheep in a pen," one soldier wrote. Paved with bodies piled high, the road became known as Bloody Lane. Although the Confederate center was now foundering, the ever-hesitant McClellan decided against the assault that would break it completely, claiming it wouldn't be prudent to attack again.
Confederate dead at Bloody Lane, 1862. Source: United States Library of Congress.
In the third major action of Antietam, Gen. Ambrose Burnside's 12,500 Union troops struggled to cross a stone bridge over the creek, but they were held off for hours by just 400 Georgia riflemen shooting from a bluff beyond the bridge.
Eventually the Confederates were forced to retreat, but 3,000 new Rebel troops arrived from Harpers Ferry and attacked Burnside's flank. Burnside pleaded for reinforcements, but McClellan once again declined to advance his troops. As the day ended, Burnside fell back to the stone bridge and fighting tapered off.
Lee lost a quarter of his army. Vastly outnumbered, he expected McClellan to finish him off, which President Abraham Lincoln also expected: "Destroy the Rebel army if possible," the president wired. Once again McClellan did nothing.
Frustrated with McClellan's reluctance, Lincoln headed to the battlefield in person to persuade the general to pursue Lee's retreating army. Despite Lincoln's intervention, McClellan dawdled for weeks. On Nov. 5, the president finally relieved him of command.
At the start of the Maryland invasion, Lincoln had reportedly vowed that "if God gave us the victory in the approaching battle," he would consider it "an indication of Divine Will" to proceed with emancipation. After Union forces won the day at Antietam, Lincoln declared: "God had decided this question in favor of the slaves." On Sept. 22, just days after the battle, Lincoln read the preliminary Emancipation Proclamation to his Cabinet; the next day he ordered it distributed to newspapers and the army. The stage was set for the abolition of slavery.
Today, more than 100 monuments, most dedicated to Union soldiers, mark the landscape at Antietam National Battlefield; the Southern states were too economically and politically devastated after the war to fund memorials. But the site needs attention so it may be preserved for future generations. The roof of the grand Maryland Monument, which memorializes soldiers on both sides, requires repair and is currently closed. Nonprofit Antietam Partner seeks tax-deductible donations to repair the monument and also to acquire land to restore the field's battle-era appearance and to reconstruct some of the original landmarks.
Antietam National Battlefield. Source: National Park Service.
Preserving Antietam is not only a way to remember the dead who fought there; it is also a way to preserve the hope that the nation will never again face a day as bloody as Sept. 17, 1862.
Source: Getty Images.
Renee Valois is a contributing writer for the magazine.
Top photo of Confederate Dead waiting for burial after the Battle of Antietam, source: United States Library of Congress. Painting by Thulstrup, 1887, source: Old Print Shop, New York City.