Of all the killing grounds of the Civil War, one small patch of farmland holds a place apart. To the soldiers who survived that morning it was never just a cornfield. For the rest of their lives, when veterans of Antietam spoke of The Cornfield, everyone knew exactly what they meant, and many could not speak of it at all. It was an ordinary thirty-acre field of ripe corn belonging to a farmer named David Miller, on the northern end of the Antietam battlefield. At dawn on September 17, 1862, the corn stood tall, higher than a man's head, wet with dew, hiding whatever waited inside it. Within a few hours it would become the most concentrated scene of slaughter in American history. The horror began around 5:30 in the morning. Union troops under Joseph Hooker advanced south toward a small whitewashed church, and as they came, Hooker spotted the glint of sunlight on bayonets in the corn. Confederate infantry was hidden in the rows. Hooker halted his advance and did something coldly practical. He brought up his artillery and had battery after battery pour shell and canister directly into the standing corn, sweeping it with iron at close range. Men who were there described what the shells did to the hidden ranks in language that never left them. Whole lines of Confederate soldiers were cut down where they crouched, unseen, torn apart in the corn before the infantry even closed. Then the foot soldiers went in, and the field became a nightmare that defies description. For roughly three to four hours, the Cornfield changed hands again and again, by most counts around fifteen times. A Union line would sweep through the corn, driving the enemy out the far side. Then a Confederate counterattack would come screaming back and drive the Union men out the way they had come. Then it would reverse again. And again. Each surge left another layer of bodies among the trampled stalks. The fighting was often at appallingly close range, men firing volleys into each other's faces at fifty yards, thirty yards, sometimes less, in smoke so thick they could barely see the enemy they were killing. Into this came John Bell Hood's division, including his famous Texas Brigade, who had been pulled out of line to cook their first hot meal in days and were furious at being interrupted. They charged into the Cornfield with terrible ferocity and briefly swept the Union troops back, but at a cost almost impossible to believe. Hood's division was virtually destroyed as a fighting force in a matter of minutes. His 1st Texas regiment lost around 82 percent of its men, one of the highest casualty rates any regiment suffered in any single action of the entire war. When someone later asked Hood where his fine division was, he answered simply and bitterly that his division was dead on the field. The numbers everywhere in that corn were like that. Regiments that marched in several hundred strong came out as shattered handfuls. The 12th Massachusetts lost more than half its men. Louisiana and Georgia and Wisconsin and Pennsylvania units bled out in the rows together. Men fell so thickly that survivors spoke of the dead lying in distinct lines, marking exactly where each rank had stood at the instant it was cut down. Two Union corps and much of Jackson's Confederate command were fed into this one field in succession, and chewed up in it. The most haunting testimony came from Hooker himself. Riding over the ground afterward, the hardened general wrote that every stalk of corn in the northern and greater part of the field was cut as closely as could have been done with a knife, and that the slain lay in rows precisely as they had stood in their ranks a few moments before. He had, he said, never witnessed a more bloody, dismal battlefield. Think about what that image really means. The corn had not been harvested. It had been mowed to the ground by the sheer density of bullets flying through it, and beneath that sheared stubble lay the men, arranged in the neat lines of their formations, killed so fast they never had a chance to fall out of order. By around 9:30 in the morning the fighting in the Cornfield finally guttered out, not because anyone had won it, but because the units on both sides had been so thoroughly destroyed that there was almost no one left there to keep fighting. The field simply exhausted its supply of victims. In that small space, in roughly four hours, thousands upon thousands of men had been killed or wounded. The morning phase of Antietam, centered on that field and the woods around it, accounted for a large share of the day's staggering 23,000 casualties. Afterward the Cornfield became one of the most photographed and written-about places of the war, because the images of the dead there, captured by Alexander Gardner's cameras just days later, brought the reality of the slaughter home to a stunned public for the first time. People in New York and Boston filed past photographs of the bodies lying in that trampled corn and understood, many of them for the first time, what the war actually was. The corn grew back, of course. It grows there still. But for the men who fought at Antietam, the Cornfield remained a place of nightmares to the end of their days, a single ordinary farm field where, on one September morning, the ground itself seemed to be paved with the dead.