More than 23,000 Americans were wounded, killed, or went missing in the battlefield at Sharpsburg, Maryland, on Sept. 17, 1862, making the Battle of Antietam the single most costly day in American military history.
The Union suffered more than 12,400 casualties; the Confederates suffered over 10,300. Among those casualties were many men from Connecticut. According to historian John Niven, Connecticut regiments engaged at Antietam suffered over 600 casualties, including 136 dead on the battlefield.
Overall, there were four Connecticut regiments engaged: the 8th, the 11th, the 14th, and the 16th regiments. For many of these Connecticut men, the Battle of Antietam marked their first battle experience. Many were cut down before they fired their first shot in combat.
By far the most famous Connecticut casualty at Antietam was General Joseph K. Mansfield of Middletown. He was one of six general officers to die at Antietam. A 40-year veteran of the military, Mansfield had graduated second in his West Point class in 1822. He had served with the U.S. Army in the War with Mexico in the late 1840's but had not been a field officer until being reassigned from duties in Washington, D.C., just prior to the fight at Antietam. Mansfield commanded the 12th Corps, located on the west side of Antietam Creek during the battle.
While leading his men into battle, Mansfield was shot in the chest. According to the surgeon who attended to him, he was shot in the right side of his chest, two inches from the nipple. The ball then passed out near his right shoulder blade. General Mansfield died the next day from his wound. He was 58 years old. Following a large funeral, Mansfield was buried in the Indian Hill Cemetery in Middletown. The General Mansfield House on Main Street in Middletown bears his name, as does a coastal artillery fort on Napatree Point in Westerly, RI.
Another Connecticut officer, Captain John Griswold of Lyme, suffered a fate similar to General Mansfield. Antietam Creek, which snaked through the battlefield at Sharpsburg and became the source of the battle's name, had three stone bridges, each about a mile apart. Naturally, these bridges became major points of contention during the battle. Captain John Griswold of the 11th Connecticut Regiment attempted to ford Antietam Creek to bypass one of these bridges to gain a strategic advantage. While wading through waist-deep water, Griswold was shot through the chest. He made it to the west side of the creek, proving the stream was fordable, but soon collapsed and died on the opposite shore.
Col. Henry Kingsbury, commander of the 11th Connecticut, engaged the Confederates on the stone bridge. Confederate artillery first wounded him in the foot. Shortly thereafter, canister shot from point blank range wounded him in the leg. While being transported back for aid, Kingsbury suffered two more wounds: one to the shoulder and one to the stomach. The stomach wound killed him.
The 14th Connecticut — a Middletown-based regiment — suffered dozens of casualties while marching through a ripened cornfield near the farmhouse of William Roulette. The cornfield both concealed the Connecticut soldiers and prevented them from seeing what lay ahead. As the men of the 14th emerged from the cornfield, they were systematically cut down by rifle fire from Confederates hidden by a sunken road that has famously come to be known as "Bloody Lane." Of the effects of rifle and artillery fire on the cornfield at Antietam, Major General Joseph Hooker later wrote: "...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."
Historian Niven notes that field surgeons, overwhelmed by the enormous number of wounded men, soon ran out of bandages and began to use corn leaves to bandage the wounded. Niven quotes B.F. Blakeslee of the Connecticut 16th Regiment: " In a room 12-by-20 feet a bloody table stood and around it five surgeons. A wounded man was laid on the table and it took but a few seconds for them to decide what to do and but a few minutes to do it. The amputated limbs were thrown out the window. In 48 hours there were as many as two cartloads of amputated legs, feet, arms, and hands in the pile."
Antietam marked the first time that the South had attempted to invade the North to end the war. Though both sides suffered greatly, the battle was considered a victory for the Union as the South withdrew its forces from Antietam. Most historians regard the Battle of Antietam as a turning point in the war to save the Union. Most appropriately, the battle was fought on Sept. 17, 1862, the 75th anniversary of the ratification of the United States Constitution — the very document that had established the Union that the North, including four regiments from Connecticut, sacrificed so much at Antietam to save.