At 5:30 on the morning of September 17, 1862, fog lay so thick over western Maryland that a man could not see the man beside him. Behind a whitewashed church on the far side of Antietam Creek, roughly 38,000 Confederate soldiers stretched across four miles of rolling farmland, pressed behind stone walls, crouched in a sunken road, and dug into hillsides above a narrow stream. A third of them had no shoes. Most had not eaten.
Across the creek, 75,000 Union soldiers had been waiting since the previous afternoon. Their commanding general had positioned 300 guns along the ridgeline, studied the ground, and done what he always did. He hesitated. In the next twelve hours, those four miles of Maryland farmland would become the bloodiest single day in American history.
Nearly 23,000 men would be killed, wounded, or left dying. A 40-acre cornfield would change hands fifteen times. A sunken farm road would fill with bodies stacked four deep. A twelve-foot stone bridge would cost an entire Union corps an afternoon of carnage to cross, even though the creek beneath it was shallow enough to wade.
When it was over, President Abraham Lincoln would conclude that the most important battle of the war had not been lost by the enemy. It had been squandered by his own general. Five days before the battle, a Union corporal had found Lee’s entire invasion plan lying in a field, wrapped around three cigars. The Union commander held the enemy’s battle orders in his hands.
He knew where every Confederate division was, how separated they were, and how vulnerable each was on its own. He still could not finish the job. Robert E. Lee was fifty-five, a Virginia aristocrat who had opposed secession but chose Virginia over his oath to the United States.
In the first week of September 1862, he decided to invade the North. His Army of Northern Virginia, closer to 38,000 men who could actually fight, crossed the Potomac at White’s Ford on September 4 and marched into Maryland. These men had just won at Second Bull Run. They were veterans.
They were also starving. Living on green corn and unripe apples, many barefoot, they followed Lee because he was the only Confederate general who won. Lincoln was fifty-three, a self-educated Illinois lawyer who had buried two sons and watched his generals lose battle after battle. The general he could not stop defending was George Brinton McClellan, thirty-five years old, a Philadelphia railroad engineer called the Young Napoleon.
McClellan had done something genuinely remarkable: after the disaster at First Bull Run, he had forged 87,000 raw volunteers into the Army of the Potomac, the most powerful fighting force on the continent. What he could not do, and what Lincoln was beginning to suspect he would never do, was use it. By September 15, Lee had concentrated roughly 25,000 men on the high ground west of Antietam Creek near the village of Sharpsburg. The ground favored the defense.
The creek ran thirty to fifty yards wide with steep banks. A sunken farm road worn twenty feet below the fields by wagon traffic cut across the center. A narrow stone bridge anchored the south. McClellan’s 75,000 arrived east of the creek by evening.
He had a two-to-one advantage. He knew it. And he delayed. The intelligence in his hands was extraordinary.
On September 13, Corporal Barton Mitchell of the 27th Indiana Infantry, a twenty-three-year-old farm boy foraging near Frederick, Maryland, picked up a paper lying in the grass wrapped around three cigars. It was Special Orders No. 191, Lee’s complete invasion plan, detailing every division, every route, every objective. Lee’s army was split into pieces spread across twenty miles, each piece isolated and vulnerable.
An aide later recalled that McClellan read the document and said, “My God, McClellan has got Lee’s plans. ” He held the location of every Confederate division. And he took eighteen hours to act on it. He attacked the passes at South Mountain on the morning of September 14.
The fighting was fierce, and the Union took the passes, but the cost was over 3,000 casualties. Lee’s army was still divided, the road to Sharpsburg clear. McClellan did not pursue through the night. He waited for morning.
Every hour he waited was an hour Lee used. On the night of September 15, Lee’s officers counseled retreat. The army was outnumbered, exhausted, with its back to the Potomac River. A defeat meant annihilation.
Lee listened, then told his commanders they would not fall back. He was betting his entire army on one man’s psychology: that McClellan would attack in pieces, one corps at a time, never all at once. Against a piecemeal attack, even an outnumbered army could hold. He was right.
The fog lifted at 5:30 on the morning of September 17, revealing a cornfield eight to ten feet tall, four hundred yards wide and twelve hundred yards deep, with the Dunker Church on the far rise. Joseph Hooker’s First Corps stepped into the corn at 6:00: 9,000 men with bayonets fixed, while 30 guns fired over their heads. John Bell Hood’s Texans were waiting, 2,700 men pulled from a cooking fire, many shirtless in the early heat. They charged into the cornfield, and at ranges under fifty yards the two lines poured rifle fire into each other through standing stalks.
Hood would write his wife the next day with a single sentence: his division went in 2,800 strong and came out 400. By 10:00, every stalk in the cornfield had been cut down by gunfire. The field was flat, open, and carpeted with dead. Neither side held it.
Neither side had broken through. The battle shifted south, to the sunken road. D. H.
Hill had 2,500 men lying flat behind fence rails on the lip of the road, invisible from fifty yards. William French’s division marched uphill in neat lines toward what appeared to be an empty ridge. At one hundred yards, the wall erupted. The Irish Brigade, 1,200 men under green flags with golden harps, charged across open ground and was met with volley after volley.
540 of the 1,200 were killed or wounded in twenty minutes. Six Union assaults ground on for three and a half hours. The Confederates were fighting with empty rifles by noon, using bayonets and rocks. The break came when a Union regiment found an angle on the road’s flank and poured enfilade fire down its length.
When Union soldiers crested the ridge, they saw bodies stacked so thick a man could walk the entire road without touching the ground. The center of Lee’s line was broken. The road to Sharpsburg was open. McClellan, from his hilltop a mile away, sent no one through it.
At the southern end of the battlefield, Burnside’s 12,000 men were ordered to cross Antietam Creek at a narrow stone bridge defended by 500 Georgians under Robert Toombs. Four assaults were repulsed. The creek was fordable waist-deep five hundred yards upstream, but no one on the Union side looked at a map, and Burnside followed orders. The sixth assault succeeded at about 1:00.
By 4:00, Burnside’s men were on the outskirts of Sharpsburg, and Lee’s right flank was crumbling. Then a dust cloud appeared on the southern horizon. A. P.
Hill’s division had marched seventeen miles from Harpers Ferry in eight hours. Fresh troops slammed into Burnside’s exposed left flank at 3:30. Burnside’s advance stopped, then reversed. His exhausted men were driven back toward the creek.
By 5:30, the guns fell silent. In twelve hours, roughly 23,000 men had been killed, wounded, or left to die on four miles of Maryland farmland. At his headquarters, a mile from the nearest fighting, McClellan still had 20,000 fresh troops who had not fired a shot. He believed Lee had reserves.
His intelligence chief, Allan Pinkerton, had told him Lee commanded at least 91,000 men, a fantasy McClellan had needed to believe since the Peninsula campaign. Lee had committed every man he had. Behind the Confederate line was only open road and the Potomac. On the night of September 18, Lee ordered his army across the Potomac at Boteler’s Ford.
By dawn, the Army of Northern Virginia was back in Virginia. McClellan did not pursue. Lincoln read the dispatches and understood what had happened. On September 22, five days after the battle, Lincoln issued the preliminary Emancipation Proclamation.
He had been waiting for a victory to announce it, and Antietam, however incomplete, was the closest thing he had. The war was now officially about ending slavery. Lincoln was not grateful. He was furious.
He visited McClellan’s camp on October 3, walked the battlefield, saw 80,000 men fully supplied and resting while Lee rebuilt in Virginia. He urged pursuit. McClellan agreed and did nothing. On October 24, Lincoln sent the telegram that every historian recognizes as the final straw.
McClellan had complained his cavalry horses were tired. Lincoln replied, “Will you pardon me for asking what the horses of your army have done since the Battle of Antietam that fatigues anything? ”
On November 7, 1862, a telegram arrived at McClellan’s headquarters at Warrenton. He was relieved of command.
His replacement was Ambrose Burnside, the man who could not take the bridge. McClellan’s troops wept and rioted as he rode out of camp for the last time. He ran against Lincoln in 1864 on a peace platform and lost badly. He died in 1885 at age fifty-eight.
His memoirs still insisted Lee had 120,000 men at Antietam. Burnside fared no better. Six weeks after taking command, he launched the Army of the Potomac into the slaughter at Fredericksburg, a disaster so one-sided he was relieved within weeks. If McClellan had committed even one fresh corps through the broken center at Bloody Lane, he would have cut Lee’s army in half.
The war might have ended in September 1862 instead of April 1865. Instead, Lincoln did not fire McClellan because he lost at Antietam. He fired him because he won, and it still was not enough.