September 17, 1862---The Battle of Antietam (Sharpsburg)

SEPTEMBER 17, 1862:       

The Battle of Antietam Creek (The Battle of Sharpsburg).  

The single bloodiest day on the North American continent---ever---began with the South having had three strokes of luck. 

Robert E. Lee’s anemic force of 18,000 men had been bolstered, first by the overnight arrival of the troops that abandoned South Mountain, and second, by the quick response of Stonewall Jackson, who led his men, victorious at Harper’s Ferry, at the double quick time march, to aid Lee. Lee, who started with a token force now  had 40,000 men. 

The South’s third stroke of luck was General McClellan, the Union commander, who, though having a copy of Lee’s battle plan, dithered (as was his habit) allowing Lee to be reinforced. 

McClellan was also convinced, despite every evidence, that Lee’s 40,000 man force somehow outnumbered his 80,000 man force. Even the arrival of Contrabands with stolen disposition plans, did not convince McClellan, who disliked and mistrusted black people. 

  

While dithering, McClellan moved his troops into an assault formation that Robert E. Lee, with his superior Intelligence, was able to counter.

The Battle of Antietam resolved itself into three interlinked partially simultaneous, partially consecutive actions: 

1. The Battle of The Dunker Church: 

The Battle of Antietam opened at 5:30 AM with an attack down the Hagerstown Turnpike by the Union First Corps. First Corps’ objective was the plateau on which sat a modest whitewashed building belonging to a sect of German Baptists, the United Brethren (”The Dunkers”), similar to the Amish and the Mennonites. First Corps was made up of 9,000 men, little more than the 8,000 defenders commanded by Stonewall Jackson, and this disparity was more than overcome by the Confederates' strong defensive positions on the high ground around the Dunker Church.

 

To attack the little plateau, the Union forces had to break from the cover of the North Woods and cross Miller’s cornfield (soon to be infamous as “The Cornfield”).   

As soon as First Corps emerged into The Cornfield, a blistering artillery barrage began, which was immediately countered by an even stronger Union response. Under this “artillery hell” (as it was described) Rebels in The Cornfield attacked Yankees in The Cornfield. 

Shot and shell was thick as a plague of locusts as frenzied men beat each other to death with rifle butts, stabbed each other with bayonets, and pummelled each other with fists even as they were being blown apart by canister and solid shot from the cannons.

Reinforcements coming to aid their respective sides were thrown into this human meat grinder; a Union Brigade came screaming out of the East Woods in an attempt to box in the Confederates in The Cornfield.

Most of the Confederates and the Union men died together. The firing was so intense that after the battle bullets were found fused together by the heat and friction when they struck each other in flight.

 

“...The most deadly fire of the war. Rifles are shot to pieces in the hands of the soldiers, canteens and haversacks are riddled with bullets, the dead and wounded go down in scores.”---Captain Benjamin Cook, 12^th Massachusetts.

Superior Union numbers began to tell. The Union’s vaunted Iron Brigade  (“The Black Hats”) entered The Cornfield and took dead aim at the Confederacy’s vaunted Louisiana Tigers who took dead aim at the Iron Brigade. 

Although both troops took horrific casualties, the Union battered open a path to the Dunker Church. However, when Lee threw his reserves into the battle, the Yankees were pushed back from the Dunker Church and back into The Cornfield which became a killing ground again. This 30-acre 1200 foot wide by 750 foot long plot of ground changed hands no less than 15 times during the battle, and was described as “the worst slaughter pen of the war”---and this war being one which would see Pickett’s Charge, Devil’s Den, The Stone Wall, The Bloody Angle, and Antietam’s own “Bloody Lane” later in the day. A Union soldier told of “a landscape turned red” in the midst of his battle-lust. Confederate General John Bell Hood described his Division as “dead on the field,” and more than eight out of ten of them were.

The Union First Corps was decimated, and 12th Corps entered the field at 7:30 AM, unfortunately in parade ground fashion, as a result of which they were cut down en masse as if they had gone over the top in World War I.

However, if McClellan had anything in his favor it was superiority in numbers (though he was blind to it) and a few 12^th Corps units survived to take the Dunker Church a second time. They held it only briefly as Confederate artillery targeted them. As 12^th Corps took the Dunker Church, units of the Union Second Corps came through the East Woods in a long and strung out horizontal formation which was beaten back slowly with heavy casualties. By 9:30, some four hours after the order to attack was given, 13,000 men lay dead or wounded on the field.

2.       The Battle of The Sunken Road:       

In an attempt to relieve the butchery in The Cornfield, the Union launched what was meant to be a diversionary attack on Lee’s center. 

This “diversion” soon became the center of the action. Although Lee had few troops in the area, D.H. Hill's men 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. This convenient berm became a shooting gallery for Confederate soldiers. 

The Union launched a series of brigade-sized assaults against Hill's improvised breastworks. The first brigade to attack was cut down by heavy rifle fire; so were the second and the third.  The Division suffered 1,750 casualties (of 5,700 men) in under an hour, and “The Bloody Lane” became clogged with the bodies of the wounded, dead and dying.  

Leading off the fourth attack of the day against the sunken road was the Irish Brigade of Brigadier General Thomas F. Meagher. 

As the Irish 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 (as he would do at Gettysburg ten months in the future) for those who were about to die. 

The Irish Brigade lost 540 men to heavy volleys before they were ordered to withdraw.

At this point, many commanders were dead, some were dying, and battlefield promotions were being given out like door prizes. 

A few commanders were, literally, hiding, either overwhelmed with terror or horror or simply unable to order more men to die. 

The slaughter at the Bloody Lane (or Sunken Road) was stopped when the Union took a grassy knoll overlooking the cart track and began pouring enfilade fire into it. Scores of Confederates died. 

Although the Grays were intended to charge the Blues to stop their assault, the wrong order was given by an inexperienced field commander, and the troops (gladly) ran for it, back toward Sharpsburg, opening a huge gap in General Lee’s lines. 

As the Union troops charged through the gap and toward Lee, Longstreet brought up artillery and blasted the hard charging men, who fell back to the Bloody Lane and The Knoll with heavy casualties. Between 9:30 AM and 1:00 PM there were inflicted almost 6,000 casualties total equally between the Blue and the Gray along the half-mile of sunken roadway. 

Although there was now nothing between the Union position and Robert E. Lee except Longstreet’s cannons and there was plenty of maneuvering room and plenty of reserves, McClellan chose not to flank the cannons and possibly even capture Lee. 

Such a victory might have ended the war, and at least certainly the battle. Instead, the Battle of Antietam ground inexorably on.

3.       The Battle of Burnside’s Bridge:       

While McClellan unproductively pondered punching a hole through Lee’s weak front wall, he ordered General Ambrose Burnside to launch a diversionary attack closer to Sharpsburg. As the Dunker Church had been the goal in the early morning, and the Sunken Road in the midday, the goal here was an arch bridge over Antietam Creek. It had a narrow approach and was narrow, making it easy for defenders to drive off any assault. And Antietam Creek was not deep; had Burnside wished, he could have simply forded it (as was done in the early morning); thus, his fixation on taking the bridge seems almost irrational. It is even more so when we consider that part of Burnside’s force did later cross the Creek at Snavely’s Ford about a mile downstream and attack Lee’s men in Sharpsburg.

 

Burnside’s first assault on the bridge, around 11:00 AM, was led by skirmishers who received fire for 15 minutes and withdrew with heavy casualties. The second assault met a similar fate. The third attempt to take the bridge was at 12:30 PM. With adequate artillery support and a promise that a recently canceled whiskey ration would be restored if they were successful, the Union troops charged, captured a light howitzer, and fired double canister across the bridge. The Confederates withdrew, giving up the bridge at a cost of more than 500 Federal casualties, opposed to 150 themselves. And they had stalled Burnside's assault for more than three hours.

Burnside's assault stalled again because he had neglected to transport ammunition across the bridge. The narrow bridge itself became a bottleneck for soldiers, artillery, and wagons, causing another two-hour delay.  By 3:30 PM General Lee had reinforced his position with additional troops from Harpers Ferry, and the oblivious Burnside was faced with 3,000 fresh troops. Burnside crossed Antietam Creek with 8,000 men, determined to cut off Lee’s escape route, and nearly seized Sharpsburg, from which the Rebels were fleeing. Unfortunately, the men from Harper’s Ferry arrived just then and turned the attack. Many were wearing captured Union uniforms from the Harper’s Ferry supply which led to confusion on the field allowing them to slip inside Union units to do their dirty work. So unnerved by this was Burnside that he retreated from Sharpsburg back across the bridge and held there, contributing nothing more to the overall battle. By 5:30 PM, twelve hours after it had begun, the Battle of Antietam Creek was over. 

Losses for the day were catastrophic on both sides. The Union had 12,401 casualties with 2,108 dead. Confederate casualties were 10,318 with 1,546 dead. This represented 25% of the Federal force and 31% of the Confederate force. Out of the 113,500 men on the field that day (about 60% of them Union) almost 23,000 were casualties. More Americans died in battle on September 17, 1862, than on any other day in the nation's military history.    

The photographs of Alexander Gardner, Matthew Brady’s protégé, tell the story of Antietam in mute, sharp, clangorous tones, unsoftened by modern photoshop and editing techniques.

For all its human toll, Antietam was at best a tactical draw though it was a strategic Union victory. For McClellan, it turned out to be his swan song as he was relieved of duty not long after Antietam. There were several reasons:

1.    McClellan wasted effort and opportunity.          

McClellan had squandered several opportunities to defeat---even to capture---Robert E. Lee on the field, when he failed to break through Lee’s front after The Bloody Lane, or through his flank at Sharpsburg. Worse yet, he failed to attack Lee’s devastated army on the day following Antietam, though Lee had not left the field. Worst, he failed to make very much use of Special Orders No. 191, which should have allowed him to chop the Army of Northern Virginia up piecemeal possibly without this horrific battle.

2.       McClellan wasted his men’s lives. 

By focusing on discrete targets (the Dunker Church, The Cornfield, Burnside’s Bridge) instead of an overall strategic movement, the Union pointlessly expended its young manpower. By having wave after wave of young men march in formation into what today we would call free-fire zones lives were cut short but the war, tragically, was not. For all their bravery and gallantry under fire, their sacrifices did not make military sense. For a man who hated to do battle because he admittedly did not like to bring his men to great harm, when McClellan brought his men to battle in earnest they paid a tremendous price because of his hesitancy. This terrible error was compounded when he explained the near-draw as a consequence of his army being dispirited. If there were ever an army not dispirited it was the Army of the Potomac on September 17, 1862.

3.       McClellan let his fears rule him. 

Convinced beyond all logic that the Rebel army outnumbered him and was better equipped, McClellan fell prey to the same bogeymen he had always listened to before. It is hard to say why. Perhaps Little Mac was, at base, a coward, or maybe he just did not care whether the North won or not; he had backed away from apparent victory several times (such as at Richmond) but he had never taken a battle so far at so much cost and gained so comparatively little. In any event, he would soon be gone. 

Lee, for his part, erred (as he would again at Gettysburg) in believing that pro-Southern sentiment was overwhelming in the lower North. Despite the fact that Secessionists and Copperheads were vociferous they were relatively powerless and became more so as the war wore on. He also attempted an invasion of the North with far too few men and materiel, and a relatively poor understanding of the Union soldier. Yes, the Blue had broken at Bull Run, the Yankee had backed away from Richmond, and no, the Union could not boast of military officers of the caliber of Lee, Jackson and Stuart. It struggled with Halleck, Pope, and McClellan instead. But the Union soldier, when properly led and motivated, was at least the equal of the Confederate soldier. At Antietam, Billy Yank proved his mettle.  

Very importantly, Lee had been driven out of the North with terrible losses. He would not return for ten months. In those intervening months the Union would grow stronger and the Confederacy, already withering, would take an axe-blow that would ultimately prove fatal. 

 

And most crucially, the victory at Antietam, though incomplete and imperfect, would give President Lincoln the opportunity he had been waiting for, to issue the Emancipation Proclamation.