Morning phase Hooker and Hood attack The battle opened at dawn (about 5:30 a.m.) on September 17 with an attack down the Hagerstown Turnpike by the Union I Corps under Joseph Hooker. Hooker's objective was the plateau on which sat the Dunker Church, a modest whitewashed building belonging to a congregation of
German Baptist Brethren. Hooker had approximately 8,600 men, little more than the 7,700 defenders under Stonewall Jackson, and this slight disparity was more than offset by the Confederates' strong defensive positions. Abner Doubleday's division moved on Hooker's right, James Ricketts's moved on the left into the East Woods, and George Meade's
Pennsylvania Reserves division deployed in the center and slightly to the rear. Jackson's defense consisted of the divisions under Alexander Lawton and John R. Jones in line from the
West Woods, across the Turnpike, and along the southern end of Miller's Cornfield. Four brigades were held in reserve inside the West Woods. As the first Union men emerged from the North Woods and into the
Cornfield, an artillery duel erupted. Confederate fire was from the horse artillery batteries under Jeb Stuart to the west and four batteries under Colonel
Stephen D. Lee on the high ground across the pike from the Dunker Church to the south. Union return fire was from nine batteries on the ridge behind the North Woods and twenty 20-pounder
Parrott rifles, 2 miles (3 km) east of Antietam Creek. The conflagration caused heavy casualties on both sides and was described by Colonel Lee as "artillery Hell." Seeing the glint of Confederate bayonets concealed in the Cornfield, Hooker halted his infantry and brought up four batteries of artillery, which fired shell and canister over the heads of the Federal infantry into the field. A battle began, with considerable
melee action with rifle butts and bayonets due to short visibility in the corn. Officers rode about cursing and yelling orders no one could hear in the noise. Rifles became hot and fouled from too much firing; the air was filled with a hail of bullets and shells. Meade's 1st Brigade of Pennsylvanians, under Brigadier General Truman Seymour, began advancing through the East Woods and exchanged fire with Colonel James Walker's brigade of Alabama, Georgia, and North Carolina troops. As Walker's men forced Seymour's back, aided by Lee's artillery fire, Ricketts's division entered the Cornfield, also to be torn up by artillery. Brigadier General Abram Duryée's brigade marched directly into volleys from Colonel Marcellus Douglass's Georgia brigade. Enduring heavy fire from a range of and gaining no advantage because of a lack of reinforcements, Duryée ordered a withdrawal. The reinforcements that Duryée had expected—brigades under Brigadier General George L. Hartsuff and Colonel William A. Christian—had difficulties reaching the scene. Hartsuff was wounded by a shell, and Christian dismounted and fled to the rear in terror. When the men were rallied and advanced into the Cornfield, they met the same artillery and infantry fire as their predecessors. As the superior Union numbers began to tell, the Louisiana "Tiger" Brigade under Harry Hays entered the fray and forced the Union men back to the East Woods. The casualties received by the 12th Massachusetts Infantry, 67%, were the highest of any unit that day. The Tigers were beaten back eventually when the Federals deployed an artillery battery in the Cornfield. Point-blank fire slaughtered the Tigers, who lost 323 of their 500 men. While the Cornfield remained a bloody stalemate, Federal advances a few hundred yards to the west were more successful. Brigadier General John Gibbon's 4th Brigade of Doubleday's division (recently named the
Iron Brigade) began advancing down and astride the turnpike, into the cornfield, and in the West Woods, pushing aside Jackson's men. They were halted by a charge of 1,150 men from Starke's brigade, leveling heavy fire from away. The Confederate brigade withdrew after being exposed to fierce return fire from the Iron Brigade, and Starke was mortally wounded. The Union advance on the Dunker Church resumed and cut a large gap in Jackson's defensive line, which teetered near collapse. Although the cost was steep, Hooker's corps was making steady progress. Confederate reinforcements arrived just after 7a.m. The divisions under McLaws and Richard H. Anderson arrived following a night march from Harpers Ferry. Around 7:15, General Lee moved George T. Anderson's Georgia brigade from the right flank of the army to aid Jackson. At 7a.m., Hood's division of 2,300 men advanced through the West Woods and pushed the Union troops back through the Cornfield again. They were aided by three brigades of D.H. Hill's division arriving from the Mumma Farm, southeast of the Cornfield, and by Jubal Early's brigade, pushing through the West Woods from the Nicodemus Farm, where they had been supporting Jeb Stuart's horse artillery. Some officers of the Iron Brigade rallied men around the artillery pieces of Battery B, 4th U.S. Artillery, and Gibbon himself saw to it that his previous unit did not lose a single caisson. Hood's men bore the brunt of the fighting, however, and paid a heavy price—60% casualties—but they were able to prevent the defensive line from crumbling and held off the I Corps. When asked by a fellow officer where his division was, Hood replied, "Dead on the field."
Mansfield and Sedgwick Hooker's men had also paid heavily but without achieving their objectives. After two hours and 2,500 casualties, they were back where they started. The Cornfield, an area about deep and wide, was a scene of indescribable destruction. It was estimated that the Cornfield changed hands no fewer than 15 times in the course of the morning. Maj.
Rufus Dawes, who assumed command of Iron Brigade's 6th Wisconsin Regiment during the battle, later compared the fighting around the Hagerstown Turnpike with the stone wall at
Fredericksburg,
Spotsylvania's "Bloody Angle", and the slaughter pen of
Cold Harbor, insisting that "the Antietam Turnpike surpassed them all in manifest evidence of slaughter." Hooker was reinforced by the 7,200 infantrymen of Mansfield's XII Corps, which had been held in a loosely defined reserve role. Half of Mansfield's men were raw recruits, and Mansfield was also inexperienced, having taken command only two days before. Although he was a veteran of 40 years' service, he had never led large numbers of soldiers in combat. Concerned that his men would bolt under fire, he marched them in a formation that was known as "column of companies, closed in mass," a bunched-up formation in which a regiment was arrayed ten ranks deep instead of the normal two. As his men entered the East Woods, they presented an excellent artillery target, "almost as good a target as a barn." Mansfield himself was shot in the chest and died the next day. Alpheus Williams assumed temporary command of the XII Corps. The new recruits of Mansfield's 1st Division made no progress against Hood's line, which was reinforced by brigades of D. H. Hill's division under Colquitt and McRae. The 2nd Division of the XII Corps, under
George Sears Greene, however, broke through McRae's men, who fled under the mistaken belief that they were about to be trapped by a
flanking attack. This breach of the line forced Hood and his men, outnumbered, to regroup in the West Woods, where they had started the day. Greene was able to reach the vicinity of Dunker Church, and drove off Stephen Lee's batteries. Louisiana Brigade, on the Hagerstown Turnpike, north of the Dunker Church.Photograph by
Alexander Gardner Hooker attempted to coordinate the assault, but a Confederate sharpshooter spotted the general and his white horse and shot Hooker through the foot. Command of his I Corps was assigned to Meade by Hooker. Ricketts had seniority over Meade, but McClellan backed Hooker's decision to place Meade in command of the corps. With Hooker removed from the field, there was no general left with the authority to coordinate the remaining troops on the field. In an effort to turn the Confederate left flank and relieve the pressure on Mansfield's men, Sumner's II Corps was ordered at 7:20 a.m. to send two divisions into battle. Sedgwick's division of 5,400 men was the first to ford the Antietam, and they entered the East Woods with the intention of turning left and forcing the Confederates south into the assault of Ambrose Burnside's IX Corps. However, the plan went awry. They became separated from William H. French's division, and at 9a.m. Sumner, who was accompanying the division, launched the attack with an unusual battle formation—the three brigades in three long lines, men side-by-side, with only 50 to separating the lines. They were assaulted first by Confederate artillery and then from three sides by the divisions of Early, Walker, and McLaws, and in less than half an hour Sedgwick's men were forced to retreat in great disorder to their starting point with over 2,200 casualties, including Sedgwick himself, who was taken out of action for several months by a wound. Sumner has been condemned by most historians for his "reckless" attack, his lack of coordination with the I and XII Corps headquarters, losing control of French's division when he accompanied Sedgwick's, failing to perform adequate reconnaissance prior to launching his attack, and selecting the unusual battle formation that was so effectively flanked by the Confederate counterattack. Historian M. V. Armstrong's recent scholarship, however, has determined that Sumner did perform appropriate reconnaissance and his decision to attack where he did was justified by the information available to him. At around 9:45a.m., Williams was tasked with reinforcing Sumner, and he sent two XII Corps regiments towards the Hagerstown Turnpike. The two regiments were confronted by the division of John G. Walker, newly arrived from the Confederate right. Walker's men repulsed the two Union regiments, and one of the Confederate brigades, commanded by Colonel
Van H. Manning, attacked Greene's position near the Dunker Church around 10a.m. After repulsing Manning's brigade, Greene's soldiers counterattacked into the West Woods. The fighting died down around the Dunker Church, and shifted towards Lee's center. The morning phase ended with casualties on both sides of almost 13,000, including two Union corps commanders.
Midday phase Opening assaults on the Sunken Road By midday, the action had shifted to the center of the Confederate line. Sumner had accompanied the morning attack of Sedgwick's division, but another of his divisions, under French, lost contact with Sumner and Sedgwick and inexplicably headed south. Eager for an opportunity to see combat, French found skirmishers in his path and ordered his men forward. By this time, Sumner's aide (and son) located French, described the terrible fighting in the West Woods and relayed an order for him to divert Confederate attention by attacking their center. French confronted D.H. Hill's division. Hill commanded about 2,500 men, less than half the number under French, and three of his five brigades had been torn up during the morning combat. This sector of Longstreet's line was theoretically the weakest. Hill's men, however, were in a strong defensive position, atop a gradual ridge, in a sunken road worn down by years of wagon traffic, which formed a natural trench. French launched a series of brigade-sized assaults against Hill's improvised breastworks at around 9:30 a.m.. The first brigade to attack, mostly inexperienced troops commanded by Brigadier General Max Weber, was quickly cut down by heavy rifle fire; neither side deployed artillery at this point. The second attack, more raw recruits under Colonel Dwight Morris, was also subjected to heavy fire, but managed to beat back a counterattack by the Alabama Brigade of Robert Rodes. The third, under Brigadier General Nathan Kimball, included three veteran regiments, but they also fell to fire from the sunken road. French's division suffered 1,750 casualties (of his 5,700 men) in under an hour. Reinforcements were arriving on both sides, and by 10:30 a.m. Robert E. Lee sent his final reserve division—some 3,400 men under Major General Richard H. Anderson—to bolster Hill's line and extend it to the right, preparing an attack that would envelop French's left flank. But at the same time, the 4,000 men of Major General Israel B. Richardson's division arrived on French's left. This was the last of Sumner's three divisions, which had been held up in the rear by McClellan as he organized his reserve forces. Leading off the fourth attack of the day against the sunken road was the
Irish Brigade of
Brigadier General Thomas F. Meagher. As they advanced with emerald green flags snapping in the breeze, a regimental chaplain, Father
William Corby, rode back and forth across the front of the formation shouting words of conditional
absolution prescribed by the
Roman Catholic Church for those who were about to die. The mostly
Irish immigrants lost 540 men to heavy volleys before they were ordered to withdraw. General Richardson personally dispatched the brigade of Brigadier General
John C. Caldwell into battle around noon (after being told that Caldwell was in the rear, behind a haystack), and finally the tide turned. Anderson's Confederate division had been little help to the defenders after General Anderson was wounded early in the fighting. Other key leaders were lost as well, including George B. Anderson (no relation; Anderson's successor, Colonel
Charles C. Tew of the 2nd North Carolina, was killed minutes after assuming command) and Colonel
John B. Gordon of the 6th Alabama. The Confederate command structure was becoming disorganized.
Collapse of the Sunken Road As Caldwell's brigade advanced around the right flank of the Confederates, Colonel
Francis C. Barlow led the
61st and
64th New York forward. Barlow and Lieutenant Colonel
Nelson Miles saw a weak point in the line and maneuvered their troops into a position that allowed them to pour
enfilade fire into the Confederate line, turning it into a deadly trap. In attempting to wheel around to meet this threat, a command from Rodes was misunderstood by Lt. Colonel James N. Lightfoot, who had succeeded Gordon. Lightfoot ordered his men to about-face and march away, an order that all five regiments of the brigade thought applied to them as well. Confederate troops streamed toward Sharpsburg, their line lost. Most of George Anderson's brigade withdrew as well, caught up in the retreat of Richard Anderson's division. Richardson's men were in hot pursuit when massed artillery hastily assembled by General Longstreet drove them back. A counterattack with 200 men led by D.H. Hill got around the Federal left flank near the sunken road, and although they were driven back by a fierce charge of the 5th New Hampshire, this stemmed the collapse of the center. Reluctantly, Richardson ordered his division to fall back to north of the ridge facing the sunken road. His division lost about 1,000 men. Colonel Barlow was severely wounded, and Richardson mortally wounded. Winfield S. Hancock assumed division command. Although Hancock would have an excellent future reputation as an aggressive division and corps commander, the unexpected change of command sapped the momentum of the Federal advance. The carnage from 9:30 a.m. to 1:00 p.m. on the sunken road gave it the name
Bloody Lane, leaving about 5,600 casualties (Union 3,000, Confederate 2,600) along the road. And yet, a great opportunity presented itself. If this broken sector of the Confederate line were exploited, Lee's army would be divided in half and possibly defeated. There were ample forces available to do so. There was a reserve of 3,500 cavalry and the 10,300 infantrymen of General Porter's V Corps, waiting near the middle bridge, a mile away. The VI Corps, under Major General William B. Franklin, had just arrived with 12,000 men. The Rebels, under Manning, had made a second assault on the high ground to the left (held by Greene) overlooking the road that temporarily around noon, but Smith's Division of VI Corps recaptured it. Franklin was ready to exploit this breakthrough, but Sumner, the senior corps commander, ordered him not to advance. Franklin appealed to McClellan, who left his headquarters in the rear to hear both arguments but backed Sumner's decision, ordering Franklin and Hancock to hold their positions. McClellan never lost this ground for the remainder of the battle and eventually had amassed 44 guns on it. After the war, the story spread that later in the day, the commander of the other reserve unit near the center, the V Corps, Major General Fitz John Porter, heard recommendations from Major General George Sykes, commanding his 2nd Division, that another attack be made in the center, where V Corps skirmishers were driving weak Confederate defenses on Cemetery Hill, an idea that intrigued McClellan. However, Porter is said to have told McClellan, "Remember, General! I command the last reserve of the last Army of the Republic", a statement which it is claimed caused McClellan to abandon thoughts of an attack in the center. While the Union skirmisher operations in the center were showing promise of a major breakthrough and were called off, Porter's alledged statement is likely a fiction, and his role in the lost opportunity at the center has been embellished. The historian D. Scott Hartwig concludes that while Porter "was not in favor of sending more troops across [Antietam Creek], he did not discourage using those already on the other side of it to support a push toward Cemetery Hill", although Hartwig believes that Porter does ultimately bear some of the responsibility for the missed opportunity. The tale may partially be a misremembering of a later conversation regarding sending reinforcements to Burnside.
Afternoon phase Burnside's Bridge The action moved to the southern end of the battlefield. McClellan's plan called for Major General
Ambrose Burnside and the IX Corps to conduct a diversionary attack in support of Hooker's I Corps, hoping to draw Confederate attention away from the intended main attack in the north. However, Burnside was instructed to wait for explicit orders before launching his attack, and those orders did not reach him until 10a.m. Burnside was largely passive during preparations for the battle. The IX Corps had a clumsy command structure - Burnside had earlier commanded one wing of the Union army, composed of the I and IX Corps. Despite the I Corps being detached from Burnside's control, he still acted as if he were a wing commander. Orders for the IX Corps went to Burnside, who then passed them on directly to Jacob Cox. Cox had assumed temporary command of the corps after the death of Reno at South Mountain. Burnside had four divisions (12,500 troops) and 50 guns east of Antietam Creek. Facing him was a force that had been greatly depleted by Lee's movement of units to bolster the Confederate left flank. At dawn, the divisions of Brig. Gens. David R. Jones and John G. Walker stood in defense, but by 10a.m. all of Walker's men and Colonel George T. Anderson's Georgia brigade had been removed. Jones had only about 3,000 men and 12 guns available to meet Burnside. Four thin brigades guarded the ridges near Sharpsburg, primarily a low plateau known as Cemetery Hill. The remaining 400 men—the 2nd and 20th Georgia regiments, under the command of Brigadier General Robert Toombs, with two artillery batteries—defended Rohrbach's Bridge, a three-span, 125-foot (38 m) stone structure that was the southernmost crossing of the Antietam. It would become known to history as
Burnside's Bridge because of the notoriety of the coming battle. The bridge was a difficult objective. The main road leading to it was exposed to enemy fire, but a farm lane allowed a more protected approach to around from the bridge. The bridge was dominated by a steep bluff on the west bank, and trees and an old quarry provided cover for defenders. The Confederates also strengthened their position with breastworks made from logs and fence rails. Historians question why Burnside spent so much time at the bridge on Antietam Creek when the creek could have been forded "at a variety of places out of enemy range". The commanding terrain across the sometimes shallow creek made crossing the water a comparatively easy part of a difficult problem. Burnside concentrated his plan instead on storming the bridge while simultaneously crossing a ford McClellan's engineers had identified a half mile (1 km) downstream, but when Burnside's men reached it, they found the banks too high to negotiate. While Colonel George Crook's Ohio brigade prepared to attack the bridge with the support of Brigadier General Samuel Sturgis's division, the rest of the Kanawha Division and Brigadier General Isaac Rodman's division struggled through thick brush trying to locate Snavely's Ford, 2 miles (3 km) downstream, intending to flank the Confederates. Crook's assault on the bridge was led by skirmishers from the 11th Connecticut, who were ordered to clear the bridge for the Ohioans to cross and assault the bluff. After receiving punishing fire for 15 minutes, the Connecticut men withdrew with 139 casualties, one-third of their strength, including their commander, Colonel Henry W. Kingsbury, who was fatally wounded. Crook's main assault went awry when his unfamiliarity with the terrain caused his men to reach the creek a quarter mile (400 m) upstream from the bridge, where they exchanged volleys with Confederate skirmishers for the next few hours. and
51st Pennsylvania across Burnside's Bridge by
Edwin Forbes|alt=drawing of small bridge While Rodman's division was out of touch, slogging toward Snavely's Ford, Burnside and Cox directed a second assault at the bridge by one of Sturgis's brigades, led by the
2nd Maryland and
6th New Hampshire. They also fell prey to the Confederate sharpshooters and artillery, and their attack fell apart. By this time it was noon, and McClellan was losing patience. He sent a succession of couriers to motivate Burnside to move forward. He ordered one aide, "Tell him if it costs 10,000 men he must go now." He increased the pressure by sending his inspector general, Colonel
Delos B. Sackett, to confront Burnside, who reacted indignantly: "McClellan appears to think I am not trying my best to carry this bridge; you are the third or fourth one who has been to me this morning with similar orders." The third attempt to take the bridge was at 12:30 p.m. by Sturgis's other brigade, commanded by Brigadier General Edward Ferrero. It was led by the 51st New York and the
51st Pennsylvania, who, with adequate artillery support and a promise that a recently canceled whiskey ration would be restored if they were successful, charged downhill and took up positions on the east bank. Maneuvering a captured light howitzer into position, they fired double canister down the bridge and got within of the enemy. By 1p.m., Confederate ammunition was running low, and word reached Toombs that Rodman's men were crossing Snavely's Ford on their flank. He ordered a withdrawal. His Georgians had cost the Federals more than 500 casualties, giving up fewer than 160 themselves. And they had stalled Burnside's assault on the southern flank for more than three hours.
A. P. Hill arrives Burnside's assault stalled again on its own. His officers had neglected to transport ammunition across the bridge, which was itself becoming a bottleneck for soldiers, artillery, and wagons. This represented another two-hour delay. General Lee used this time to bolster his right flank. He ordered up every available artillery unit, although he made no attempt to strengthen D.R. Jones's badly outnumbered force with infantry units from the left. Instead, he counted on the arrival of A.P. Hill's Light Division, currently embarked on an exhausting 17 mile (27 km) march from Harpers Ferry. By 2p.m., Hill's men had reached Boteler's Ford, and Hill was able to confer with the relieved Lee at 2:30, who ordered him to bring up his men to the right of Jones. The Federals were completely unaware that 3,000 new men would be facing them. Burnside's plan was to move around the weakened Confederate right flank, converge on Sharpsburg, and cut Lee's army off from Boteler's Ford, their only escape route across the Potomac. At 3p.m., Burnside left Sturgis's division in reserve on the west bank and moved west with over 8,000 troops (most of them fresh) and 22 guns for close support. An initial assault led by the
79th New York "Cameron Highlanders" succeeded against Jones's outnumbered division, which was pushed back past Cemetery Hill and to within of Sharpsburg. Farther to the Union left, Rodman's division advanced toward Harpers Ferry Road. Its lead brigade, under Colonel Harrison Fairchild, containing several colorful
Zouaves of the
9th New York, commanded by Colonel Rush Hawkins, came under heavy shellfire from a dozen enemy guns mounted on a ridge to their front, but they kept pushing forward. There was panic in the streets of Sharpsburg, clogged with retreating Confederates. Of the five brigades in Jones's division, only Toombs's brigade was still intact, but he had only 700 men. A. P. Hill's division arrived at 3:30 p.m. Hill divided his column, with two brigades moving southeast to guard his flank and the other three, about 2,000 men, moving to the right of Toombs's brigade and preparing for a counterattack. At 3:40 p.m., Brigadier General Maxcy Gregg's brigade of South Carolinians attacked the 16th Connecticut on Rodman's left flank in the cornfield of farmer John Otto. The Connecticut men had been in service for only three weeks, and their line disintegrated with 185 casualties. The 4th Rhode Island came up on the right, but they had poor visibility amid the high stalks of corn, and they were disoriented because many of the Confederates were wearing Union uniforms captured at Harpers Ferry. They also broke and ran, leaving the 8th Connecticut far out in advance and isolated. They were enveloped and driven down the hills toward Antietam Creek. A counterattack by regiments from the Kanawha Division fell short. The IX Corps had suffered casualties of about 20% but still possessed twice the number of Confederates confronting them. Unnerved by the collapse of his flank, Burnside ordered his men all the way back to the west bank of the Antietam, where he urgently requested more men and guns. McClellan was able to provide just one battery. He said, "I can do nothing more. I have no infantry." In fact, however, McClellan had two fresh corps in reserve, Porter's V and Franklin's VI, but he was too cautious, concerned he was greatly outnumbered and that a massive counterstrike by Lee was imminent. Burnside's men spent the rest of the day guarding the bridge they had suffered so much to capture. ==Aftermath==