America's Bloodiest Day - NYTimes.com In a letter to his wife, the Union general Alpheus Williams recorded his feelings on the eve of the fighting at Antietam Creek, Md. "There was a half-dreamy sensation about it all," he wrote, "but with a certain impression that the morrow was to be great with the future fate of our country. So much responsibility, so much intense, future anxiety. The morrow was indeed great - a pivotal moment in the struggle between North and South. The battle of Antietam, or Sharpsburg, the bloodiest day in American history, rebuffed the Confederate Army of Northern Virginia's first invasion of Northern territory, convinced European nations to withhold recognition from the Confederacy, assured Republican control of the House of Representatives in the upcoming midterm elections, gave Abraham Lincoln political cover to announce the preliminary Emancipation Proclamation and finally persuaded the president that the Union could no longer afford Gen. George B. McClellan. Such momentous outcomes would have seemed unlikely a few months earlier. Throughout 1862, momentum on the battlefield had swung back and forth between the Union and Confederate armies. Northern troops had won a number of important victories, most notably at Shiloh in April, but in May Gen. Thomas J. "Stonewall" Jackson befuddled Union forces in Virginia's Shenandoah Valley. And by July 2 McClellan's much ballyhooed advance on Richmond had become a retreat, as Robert E. Lee audaciously drove federal forces back to the James River. On June 26, the Army of the Potomac was five miles from Richmond; it would not threaten the Confederate capital again until 1865. The failure of the Peninsula Campaign stunned the North. The diarist George Templeton Strong captured the mood: "We ... are in a depressed, dismal ... state of anxiety." And things quickly got worse. Lee and the Army of Northern Virginia pivoted to confront the newly formed Army of Virginia, commanded by Maj. Gen. John Pope. After a series of modest successes in the Western theater, Pope arrived in Washington, announcing "I have come to you from the West, where we have always seen the backs of our enemies." Pope got his comeuppance at the Second Battle of Bull Run on Aug. 29 and 30. After bitter and repeated assaults against Stonewall Jackson's forces, Pope was driven from the field when Gen. James Longstreet's five divisions smashed into the Union Army's left flank. Pope blamed defeat on McClellan's failure to send reinforcements; McClellan gave credence to the charge, suggesting to Lincoln on Aug. 29 that they "leave Pope to get out of his scrape & at once use all our means to make the Capitol perfectly safe." McClellan's refusal to reinforce Pope infuriated members of the cabinet, especially Secretary of War Edwin Stanton and Treasury Secretary Salmon Chase. Stanton took the extraordinary step of drafting a "remonstrance" (later softened by Attorney General Bates) to the president expressing the fear that "the destruction of our armies, the protraction of the war, the waste of our national resources, and the overthrow of the government . . . must be the inevitable consequence of George B. McClellan being continued in command." At a fractious cabinet meeting on Sept. 2, Lincoln overrode Stanton's and Chase's objections to McClellan, who unbeknownst to them had that morning accepted Lincoln's request to take command of the combined Union armies (after Gen. Ambrose Burnside had declined). Lincoln, described as "extremely distressed" by McClellan's actions, nonetheless argued that the troops were "utterly demoralized" and only McClellan could "reorganize the army and bring it out of chaos." 4, Lee led the Army of Northern Virginia across the Potomac River into western Maryland. Lee believed that the South must strike a blow that would reduce the Northern enthusiasm for the conflict or face a war of attrition it could not win. In a letter to Jefferson Davis, Lee acknowledged that "The army is not properly equipped" but that "I do not consider success impossible." The Confederacy had long contended that it was only defending itself against an aggressive "foreign invasion," but now, in Davis's words, "we are driven to protect our own country by transferring the seat of war to that of an enemy who pursues us with a relentless and apparently aimless hostility." Lee fully expected his army to be greeted as liberators in Maryland, a slave state, issuing a proclamation identifying Marylanders as "citizens of a commonwealth allied to the States of the South by the strongest social, political, and commercial ties" and promising "to aid you in throwing off this foreign yoke." But the farmers and townspeople of western Maryland, where slavery was scarce, offered the invading army scant support. Meanwhile the Northern press panicked at the presence of Lee and his army on Union soil. The New York Times wrote that people believed the government was "actually falling to pieces," while The New York Herald predicted that defeat would produce "ten or twenty petty republics of the South American school." Some among the Union military privately voiced similar distress. Brig. Gen. George Meade wrote: "The morale of the army is much impaired by recent events. I must confess I am not very sanguine of our power. But many Union foot soldiers, called upon for the first time to defend their homes, felt otherwise. "I am willing to fight as long as there is a man left in the 2nd regt before I will see the north invaded," wrote one Michigan private. Lee, who had taken McClellan's measure months earlier in Virginia, was certain the Union leader would be slow to reach western Maryland and felt secure in dividing his army. 9, he issued his famous "Lost Orders," directing Stonewall Jackson to re-cross the Potomac and circle around to attack the Union garrison at Harpers Ferry from the west, while Gen. Lafayette McLaws and Gen. John Walker were to assist by capturing Maryland and Loudon Heights overlooking Harpers Ferry. Lee, along with Longstreet's corps, would remain near Hagerstown. The inexplicable discovery, four days later, of Lee's battle plan, wrapped around three cigars lying by a roadside, was an intelligence bonanza. "Now I know what to do," McClellan crowed to one officer. To Lincoln, McClellan wrote: "I have all the plans of the rebels, and will catch them in their own trap. Will send you trophies. Ever cautious, McClellan squandered much of his advantage by waiting more than 17 hours before getting underway. Alerted by a Southern sympathizer that McClellan had a copy of his orders, Lee moved to block the Union advance. 14, some 38,000 Union troops drove west through three passes in South Mountain and by day's end had routed the 12,000 Confederate defenders. Lee became convinced that he needed to abandon his plans, but word from Jackson that Harpers Ferry would surely fall the next day restored his determination and he ordered his army to march to Sharpsburg. Had McClellan attacked at this moment, he would almost surely have overwhelmed Lee's force. But convinced as ever that he was outnumbered, McClellan hesitated east of Antietam Creek. Harpers Ferry fell to the Confederates the next day, and by midday on Sept. 16 all but three of Lee's nine divisions had arrived in Sharpsburg. A cataclysmic battle was at hand. Lee arrayed his forces in a crescent, anchored on the right by Antietam Creek and on the left by the Potomac River (for a map of the battle, click here). While the rebel army enjoyed interior lines of communication, it had its back to a river that was not easily crossed. Late in the day, Maj. Gen. "Fighting" Joe Hooker led a Union foray across Antietam Creek, thereby alerting Lee to where McClellan would strike first. Although McClellan had a sound battle plan, he failed to communicate it to his corps commanders or to coordinate their assaults. Each corps operated independently, and no more than 20,000 of his 75,000 troops were ever engaged at any one time during the battle: 20,000 troops saw no action at all. The fighting began in earnest early the next morning. Amidst a fierce artillery duel, Hooker led sustained Union assaults on Jackson's troops, who were well positioned in the West Woods near the Dunker Church (Dunkers were a German Baptist denomination). For a time, the Union troops made progress, but attack and counterattack soon transformed a now-iconic landscape - the Cornfield, the East and West Woods, the Dunker Church - into a slaughter pen. "In the time I am writing," Hooker later reported, "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, and the slain lay in rows precisely as they had stood in their ranks a few moments before." By mid-morning, the Confederates had managed to blunt the attack, and the battle's focus shifted to the center of the Southern lines. Wave after wave of federal troops sought to dislodge rebel troops from a sunken farm road, often exchanging fire at 30 paces. For over four hours, the deadly aim of Confederate cannons and troops blanketed the land with dead or wounded Union soldiers, but in the early afternoon the Yankee's superior numbers finally overran the Confederates positioned in what has been known ever since as the Bloody Lane. The carnage, captured in Mathew Brady and Alexander Gardner's famous photographs, was horrific. "In the road the dead covered the ground," remembered a Union lieutenant colonel. It seemed ... that it was the Valley of Death. I think that in the space of less than ten acres, lay the bodies of a thousand dead men and as many more wounded. At the southern end of the battlefield, three Confederate batteries and an infantry brigade commanded by Brig. Gen. Robert Toombs looked down from a steep hill onto Rohrbach Bridge. Despite repeated urging from McClellan, General Burnside made only a few desultory attempts to cross the bridge until early afternoon, when troops from New York and Pennsylvania regiments finally braved the withering fire and established themselves on the other side of Antietam Creek. By late afternoon Burnside's 13,000-man force had advanced almost to Sharpsburg, threatening to cut off Lee's line of retreat across the Potomac. At the last minute, Gen. A. P. Hill's division arrived from Harpers Ferry and drove the federal troops back to the heights near what we now know as the Burnside Bridge. By 5 p.m., the Battle of Antietam was over. Over 22,000 Americans lay dead or wounded or were among the missing: the highest single-day casualty total of the Civil War. As one particularly literate Union private later wrote, "the whole landscape for an instant turned slightly red." 17 also proved to be the war's deadliest day for civilians, when 78 workers in the Allegheny Arsenal were killed in an explosion.) An official with the Sanitary Commission wrote: "No words can convey the utter destruction and ruin. For four miles in length, and nearly a half mile in width, the ground is strewn with ... hats, caps, clothing, canteens, knapsacks, shells, and shot. ... Visit a battlefield and see what a victory costs. Lee, who was sure McClellan would not attack the next day, elected not to withdraw during the night of Sept. 17, but the following night the Army of Northern Virginia crossed the Potomac. It took more than a month - until Oct. 26 - for McClellan to follow, taking six days to do what Lee had done in one, prompting Gen. Henry Halleck to exclaim: "There is an immobility here that exceeds all that any man can conceive of." Antietam was a Union victory only because McClellan had retained command of the field. But it gave President Lincoln political cover to release the preliminary Emancipation Proclamation on Sept. 22, telling his cabinet that God "had decided this question in favor of the slaves." A month later, Lord Palmerston, the British prime minister, wrote that the British would remain neutral "lookers-on till the war shall have taken a more decided turn." And on Nov. 7, Lincoln fired McClellan: "I began to fear ... that he did not want to hurt the enemy. I saw how he could intercept the enemy on the way to Richmond. ... If he let them get away, I would remove him. He did so & I relieved him. Sources: Lawrence A. Kresier, Jr., "Defeating Lee: A History of the Second Corps Army of the Potomac"; James McPherson, "Crossroads of Freedom: Antietam"; Stephen Sears, "Landscape Turned Red: The Battle of Antietam"; Richard Slotkin, "The Long Road to Antietam: How the Civil War Became a Revolution"; Antietam On the Web; and the National Park Service's Antietam Web site. Rick Beard, an independent historian, is senior adviser for the Pennsylvania Civil War 150 and volunteer coordinator of the Civil War Sesquicentennial for the American Association for State and Local History.