— The fighting that killed or wounded 21,000 Americans in the rolling hills of Western Maryland was over in about 12 grisly hours.
But a century and a half after the bloodiest day in American military history, the struggle to preserve the ground where Union and Confederate soldiers fought the Battle of Antietam only now appears close to a declaration of victory.
As Americans gather to honor the sacrifice of those who fell on Sept. 17, 1862 — as they will do this weekend and Monday on the 150th anniversary — they will do so at one of the nation's best-preserved Civil War sites.
Unlike many of the places where Union and Confederate forces clashed, Antietam offers visitors the opportunity to view the terrain much as it appeared at the time without the visual clutter of the 20th and 21st centuries.
"It's a remarkable success story of historic preservation," said O. James Lighthizer, president of the Civil War Trust. "Antietam is the best-preserved Civil War battlefield east of Shiloh" in western Tennessee.
The prospects for Antietam's preservation didn't always appear so hopeful. For three straight years, 1989 to 1991, the National Trust for Historic Preservation listed Antietam among its 11 most threatened historic places because of the threat of encroaching development.
Now the national trust considers Antietam a model of public-private cooperation to preserve historic land — not just on the battlefield, but in the surrounding area.
"At Antietam, the context for the battlefield also is conserved," said Rob Nieweg, director of the trust's Washington field office. "The public in 2012 or 2050 will have the opportunity to envision what happened here."
Antietam was a turning point. Coming after a string of Union defeats at the hands of Robert E. Lee, it was just enough of a victory to allow Abraham Lincoln to issue the Emancipation Proclamation from a position of strength. That act, freeing the slaves in the rebellious states, changed the character of the war and the country.
The battle was the culmination of a campaign in which Lee — fresh off his successful defense of Richmond and a brilliant victory at Second Manassas — launched an invasion of Maryland, a slave state he believed was ready to be detached from the Union.
Over a two-week period, his troops seized Frederick and Hagerstown and fought the second-bloodiest battle in Maryland history at South Mountain – where 4,000 were killed and wounded 150 years ago Friday. Pushed off the mountain by a superior Union force, Lee consolidated his troops in an arc around Sharpsburg, a small Washington County town where some buildings still bear the scars of battle.
Antietam was hell in three phases.
At the Cornfield, where the battle started at dawn on Sept. 17, it is still possible to envision the rustling of fully grown stalks as thousands of attacking Union soldiers moved toward the clearing where Confederate defenders waited to mow them down.
Union troops pushed as far as the historic Dunker Church — now restored — before being thrown back by a deadly counterattack by well-concealed Confederates in the West Woods. The back-and-forth fighting was as deadly as any engagement of the war; one Texas regiment emerged with 82 percent of its soldiers dead or wounded.
Brian Baracz, a National Park Service ranger, said the carnage during the first phase of the battle was some of the worst of the entire war. "There was a soldier killed or wounded every second for four hours straight," he said. The patch of ground became the "bloodiest square mile in the history of the United States."
Along the sunken road where the second phase of the battle erupted in the middle of the field later that morning, it is readily apparent how a strong Southern defensive position became a death trap once two New York regiments seized the high ground and began firing into the Rebel flank. Filled with corpses, a section of the road would forever be known as Bloody Lane.
But by the time Union troops made their breakthrough, they were too shot up and exhausted to pursue the fleeing Rebels. Historians still debate whether Union commander Gen. George McClellan squandered an opportunity to end the war then and there by failing to throw in his reserves.
At the Burnside Bridge, where the Union launched its third attack of the battle, fighting continued through the afternoon. Viewing the bridge today, it is easy to imagine the terror of young Northerners ordered to cross Antietam Creek on a narrow span with the enemy shooting down from the heights. With a superb defensive position, a small force of Georgians repulsed two waves of Union attackers, including the 2nd Maryland.
But the eventual Union breakthrough at the bridge left the exhausted Confederate army in peril. It was only the late arrival of 3,000 troops under Confederate Gen. A.P. Hill, who had made a 17-mile march from Harpers Ferry that day, that saved Lee's army.
Susan Trail, superintendent of the Antietam National Battlefield Park, said that after Antietam, it was clear that the North was in the fight for the long haul. "After this point, there was not going to be a negotiated peace," she said. "It was becoming increasingly evident this was an all-or-nothing war."