“The Cornfield action was long glossed over by historians and storytellers, who treated it as a generic back-and-forth slugfest before moving on to recounting the battle’s many other, more easily understood actions.”

By David A. Welker

THE BATTLE OF Antietam, Sept. 17, 1862, remains America’s bloodiest single day.

The 12-hour clash created 21,699 casualties, killed 3,654, and turned many innocuous spots around quiet Sharpsburg, Maryland into national icons of death and suffering, including the Burnside Bridge, the Sunken Road, the West Woods, and the Cornfield.  Although the human cost and sacrifice connected with each of these locations justify their respective infamy, one area of the battlefield in particular stands out for both its decisiveness to events of that day and for the scale of bloodshed it witnessed. That place is Antietam’s famous Cornfield.

For many years the action fought in and around David and Margaret Miller’s cornfield was known but little understood. This is due in part to the swirling complexity of the fighting there.  Lacking easily-defined narratives and clear, distinct troop movements, the Cornfield action was long glossed over by Antietam’s historians and storytellers, who treated it as a generic back-and-forth slugfest before moving on to recounting the battle’s many other, more easily understood actions like the Sunken Road or Burnside’s Bridge. Lost, too, was the Cornfield’s impact on Antietam’s other actions and final outcome.

Confederate General Robert E. Lee set in motion the events that led to the slaughter in Millers’ cornfield, when he opened his 1862 Maryland Campaign that September. The invasion of the North came hot the heels of his crowning success at the Second Battle of Manassas and was undertaken in part to help bolster the case for European intervention on the South’s behalf while raising the cost of the war for the North. Lee, however, misjudged his opponent, Union Army of the Potomac head Major General George B. McClellan, who within two weeks of Second Manassas had rebuilt and reorganized his army before launching after Lee’s invading Confederates. Indeed, the speed of the Union pivot nearly ending Lee’s Maryland Campaign before it had barely begun. It was Major General Thomas J. “Stonewall” Jackson’s remarkable victory at Harpers Ferry that breathed new life into the Rebel invasion. Gathering at Sharpsburg, Maryland, Lee bet all on winning a decisive battle.

Lee hoped to make a defensive stand there; McClellan’s attack plan would drive the battle’s course. Opting for a one-two punch striking Lee’s flanks in turn before landing the final blow to the weakened Confederate center, McClellan set his army in motion late on Sept. 16.

Union Major General Joseph Hooker led his own I Corps and Major General Joseph K. F. Mansfield’s Federal XII Corps in spearheading the opening attack. Despite knowing his command would face the greatest, freshest Confederate resistance, he little understood that an unseen factor was at work undermining his prospects.

McClellan’ linear thinking, which drove his approach to problem solving and overcoming challenges, has often been misunderstood as excessive cautiousness. This innate personality trait—coupled with his natural determination, drive, and learned reason—was behind many of his achievements. It was evident in his days at West Point, as he climbed the army ranks, during his pre-war railroad career, and even in his marriage. Characterized by many as a flaw, his simplistic outlook enabled him to craft potentially effective battle plans—including at Antietam—but prevented much of a dynamic response to the constantly-swirling developments of battle and guiding those unpredictable events to victory. McClellan’s well-ordered battle would run into its first major test in the cornfield with decisive results.

In the battle’s opening hours, McClellan ordered Hooker to break the Confederate left by capturing the ridge upon which stood Lee’s line – near the white Dunker Church. Victory there would open McClellan’s second phase: an assault by Burnside against Lee’s right across a stone bridge over Antietam creek.

Two of Hooker’s divisions—Doubleday’s and Ricketts,’ supported by Meade’s—would drive through Miller’s cornfields to fight Confederates for the ridge. Hooker’s plan, however, came unglued almost at once.

Anticipating just such an advance, Stonewall Jackson positioned two brigades east from his main north-south line facing north toward the Cornfield the evening before the battle. These troops, along with Rebel defenders hidden in the nearby West Woods, stalled Hooker’s attack in an instant.

Throughout the morning, fresh Confederate troops sent by Generals Jackson and D. H. Hill reinforced the Rebel salient. Whether advancing to the Cornfield’s northern fence or controlling it by fire alone, Southern defenders stalled McClellan’s plans for over two hours.

Ten times the Cornfield changed hands before Hooker finally adapted. First seizing the East Woods from Jackson’s control, Hooker employed the entire massed XII Corps to strike the salient in front and flank to sweep away remaining Southern resistance. Despite finally controlling the Cornfield, Federal efforts still fell short.

For the rest of the day, Union efforts remained focused on the Cornfield. After being sidelined by wounds, Hooker passed his command to Major General Edwin V. Sumner, whose fresh II Corps nearly broke Lee’s line in the West Woods in part because it crossed the Cornfield unopposed.

Driven from the woods unexpectedly by a Confederate division under Major General Lafayette McLaws, II Corps managed to hold the Cornfield, with the help of Federal artillery. Union Brigadier General George S. Greene’s advanced from ground secured by the North’s possession of the Cornfield—site of today’s NPS visitor center. The assault very nearly broke Lee’s line, but was driven back. Yet the Cornfield remained in Federal hands.

The final attempt to complete McClellan’s first Antietam objective—Major General William Franklin’s VI Corps attack—formed centering on the Cornfield until McClellan called it off.

Facing dogged Southern resistance, with generals commanding the Union right unable to complete the key first phase, hours of daylight and thousands of lives slipped away. All the while, McClellan remained wedded to his original plan.

Yet more broadly, fighting for Miller’s Cornfield and the action it generated caused 9,913 of the Union’s 12,401 casualties and roughly 7,000 of Lee’s 9,298-man Antietam losses. Although fighting there ended hours before the wider battle had ended, both armies had been bled dry by the fight for Antietam’s bloody Cornfield.

ABOUT THE AUTHOR: David A. Welker is a professional historian for the U.S. Government and author of The Cornfield: Antietam’s Bloody Turning Point (Casemate Publishers, 2020), as well as other books and articles about the Civil War.