Now, 150 years later, the battle remains the bloodiest day in American history.
Baracz said that in 12 hours of fighting at places that are today known as The Cornfield, The West Woods, Bloody Lane and Burnside Bridge, an estimated 3.5 million bullets and 50,000 artillery rounds were fired.
About 35,000 of the 40,000 men in Lee’s Army of Northern Virginia converged on Sharpsburg the day before the battle. Several thousand Confederates under the command of Maj. Gen. Ambrose P. Hill remained at Harpers Ferry in what then was Virginia, where they raided a federal arsenal several days earlier.
Lee’s men were being pursued by 80,000 Federal troops under the command of Maj. Gen. George B. McClellan. They arrived on the eve of the battle.
McClellan ordered 15,000 men under the commands of Maj Gen. Joseph Hooker and Brig. Gen. Joseph K.F. Mansfield, to cross Antietam Creek and wait for orders to attack.
The Union’s objective was to strike the Confederate left flank under the command of Maj. Gen. Thomas “Stonewall” Jackson, who deployed his 12,000 men opposite the Cornfield and in a nearby wooded area known as the West Woods.
McClellan believed that if he crushed one of Lee’s flanks, union troops could concentrate on the Confederate center.
Baracz said that at around 5:45 a.m., Hooker’s Union troops moved out of the North Woods at the north end of the battlefield into The Cornfield.
They were met by horrific fire from more than a dozen Confederate cannons, posted near Dunker Church and about half a mile to the west at Nicodemus Heights.
Hooker later said that artillery and musket fire cut the corn so close to the ground that it looked as if someone had used a scythe.
Three of Hooker’s brigades advanced through the Confederate lines, but the attack slowed when one of the brigade commanders was wounded and another fled in fear.
As a result, Gen. Abram Duryea’s brigade of about 1,000 men was left alone in the Cornfield. At 6 a.m., the two brigades that faltered earlier rejoined the fight, but not before Duryea’s men suffered nearly 50 percent casualties.
As the Union continued to press south through the Cornfield, the Confederates advanced north from the West.
‘Dead on the field’
One Union officer said, “Simultaneously, the hostile battle lines opened a tremendous fire upon each other ... they were knocked out of the ranks by the dozens.”
Of the six regimental commanders in Confederate Col. Marcellus Douglass’ Brigade, five were killed or wounded. The brigade’s overall casualties were more than half.
Another Confederate unit, Brig. Gen. Harry Hays’ Louisiana Brigade, suffered more than 60 percent casualties in 30 minutes.
Lee’s left flank was in grave danger by 7 a.m. Around that time, Brig. Gen. John Bell Hood’s division of Texans was called to the fighting from its position behind Dunker Church, where the hungry soldiers were waiting to eat their first hot breakfast in days.
The Texans smashed into the battered but advancing Union troops, causing them to fall back.
Hood’s counterattack came at a great price. One of his units, the 1st Texas, lost 186 of its 226 men, or 82 percent.
When asked where his division was after the counterattack, Hood replied: “Dead on the field.”
Realizing they could not hold for long, Confederate commanders sent in three more brigades. At about the same time, 7,200 Union soldiers from the 12th Corps under the command of Mansfield arrived at the Cornfield.
While riding to the front of the line, Mansfield, who was given command of 12th Corps just two days earlier, was shot in the chest. He collapsed while leading his horse off the field and died the next day.
“The Cornfield changed hands roughly six times,” Baracz said. “It bounced back and forth in seesaw action.”