The Battle of Antietam: The Bloodiest Day in American History

148 years ago, the most spectacularly bloody battle in US history took place. The terrible reality of this event was its utter futility. Neither side could actually claim victory, yet this was the bloodiest day in American combat history with over 23,000 dead. More than twice as many Americans were killed or mortally wounded in combat at Antietam that day than in the War of 1812, the Mexican War and the Spanish-American War combined.

After a resounding victory at Manassas, the first major conflict of the American Civil War, Southern General Robert E. Lee wanted to compound his advantage by taking huge risk in campaigning to win Maryland for the Confederacy. This bold move had the potential to earn diplomatic recognition from Britain and France for the Southern cause, and might even compel the Union side to seek a treaty of peace. This involved Lee leading his victorious but weary troops northward across the Potomac River and into Union territory.

Lee really wanted to get Maryland into the Confederacy. It would provide him with a good location from which to attack Washington and Philadelphia, as well as allowing him access to the rich farmland of the North and major food supplies for his troops. He divided his army of 50,000, sending General “Stonewall” Jackson to capture the Union arsenal at Harper’s Ferry. He told James Longstreet to move north towards Hagerstown, Maryland.

The two armies, Southerners led by Lee and Northerners by General George B. McClellan, met in the Maryland farm fields bordering the trickling Antietam Creek near the town of Sharpsburg. While the South would always refer to this encounter as the Battle of Sharpsburg, Union soldiers named it the Battle of Antietam. From dawn till dark on that fateful day of September 17, 1862 both armies attacked ceaselessly, littering the battlefields with growing numbers of dead soldiers as they fell in their thousands.

One eye witness recalled: “The whole landscape for an instant turned red. The cornfield was so full of bodies that a man could have walked through it without stepping on the ground.” Both of the armies were densely concentrated in the Sharpsburg area, and it was a very bloody battle. The Union Army lost over 12,000 men, while the Confederate Army lost over 10,000. Neither side had gained the advantage, and when the sun went down, the fighting stopped because sheer exhaustion overtook the remaining soldiers. Lee withdrew his forces during the night and re-crossed the Potomac River.

The battle had begun with a massive attack of cannon and rifle fire. The men commanded by Union leader General Hooker began to crush the Rebel troops. Only a counterattack by a Texan force kept the Yankees from breaking the Confederate line. Several hours later, General Mansfield’s Union corps struck at the division under the command of Brigadier General Hood in the second Union attack. Mansfield was killed almost instantly, but that did no stop the fighting that raged on and on for hours, with the pattern of attack and retreat repeated again and again. Neither side seemed to get the clear advantage.

In the third attack of the day, Union commander General Sumner’s men found themselves caught in a pocket, and in a matter of minutes, over 2,000 were killed or wounded. The fourth Union attack of the day was on a heavily defended, sunken road in the middle of the Confederate position. As this was the site of some of the most bitter and desperate fighting of the day, that area was called Bloody Lane.

Even though similar numbers of troops from each side were lying dead on the battlefield, Lee’s Army had suffered the greater percentage loss. Fully one quarter of his force became casualties of this bloodiest ever battle in American history. Were you aware that more Americans were lost this day than on any other day in military history, including World War Two’s D-Day landings?

Fortunately for historians, this was the first major battle in history to be graphically recorded in photographic detail. Photographer Alexander Gardner brought back images that undoubtedly changed forever the perceptions of the public about the so-called glories and heroism of war. The stark reality of his grisly pictures spoke volumes to observers about the sheer futility of such ‘noble’ sacrifice. The bare brutality of the battlefield had been exposed to the innocent eyes of the public, and war would never again be glorified in the same way.

My sincere thanks to and for permission to use several images for this story. Information sourced from the following: 1, 2, 3, 4