September 17, 1862

September 17, 1862:

Battle of Antietam

(or Sharpsburg)

Maryland

Eastern Theater, Maryland Campaign

The Bloodiest Single Day in American History. 
In what many historians consider the most important battle of the Civil War, Maj. Gen. George B. McClellan of the Army of the Potomac finally launches an attack on Gen. Robert E. Lee and the Army of Northern Virginia, which has taken position on hilly terrain around Sharpsburg, Maryland, where he protects the roads by which is army is concentrating and his escape route across the Potomac at Boteler’s Ford.   He is also able to anchor both flanks on the Potomac to prevent the Federals from turning his line, using a large bend in the river. During the night, Stonewall Jackson has come up from Harper’s Ferry to bolster the mere 18,000 Lee had in place: now, there are over 35,000 Confederates in position. McClellan has been in position for nearly two days, and has chosen not to attack until this day. Maj. Gen. Joseph Hooker (I Corps) and Maj. Gen. Mansfield (XII Corps) are in position on the west side of Antietam Creek to strike directly southward at Lee’s left flank. Lee, however, has seen the Federal movement, and has hurried reinforcements to his left to counter it.

Little Mac’s battle plan is not known to many; he remains in his headquarters some distance from the battlefield, and ends up launching three separate assaults with three separate parts of his army—and apparently never contemplates striking simultaneously at all parts of the Rebel line, which would likely have destroyed Lee and forced him to surrender, thus bringing an early end to the war.

To see a cool animated map online for this campaign and battle, go to http://www.civilwaranimated.com/AntietamAnimation.html

But there is an even cooler one here at the site of the Civil War Trust, which features animated maps and some really excellent footage of reenactments for effect:

http://www.civilwar.org/battlefields/antietam/maps/antietam-animated-map.html
 
Part One:
Gen. Hooker advances troops from the divisions of Doubleday, Meade, and Ricketts down the Hagerstown Road between the West Woods and the East Woods, into a cornfield owned by a man named Miller. At 5:30 AM, Hooker’s I Corps steps off north of the North Woods – Dunkard Church – East Woods line to push down through the clear area by the church in order to smash the Confederate right, with Mansfield’s XII Corps right behind him.

Miller's Cornfield

　Hooker’s three divisions push into the Confederate lines with heavy losses on both sides—although on the tactical level, most fights are piecemeal, a brigade at a time.  Gen. Lee begins to bleed his right flank (under command of Gen. Longstreet) of units to bolster the beleagured left. He sends Hood with his two-brigade division, and Wofford’s Texas brigade (along with Laws’ Mississippians) smashes into the Federal lines, driving the Yankees back through the cornfield, until Federal reserves decimate the Texas regiments with well-time volley fire. 

Hooker's assault and Hood's counterattack

But Hood’s counterattack breaks the Federal momentum for a time, despite the fact that his brigades suffer 60% casualties. The Union line surges ahead again with Mansfield’s XII Corps, who are mostly green troops; Mansfield advances them in a bunched formation and they take heavy losses from Southern cannon fire. However, Greene’s Division pushes the Rebels back into the West Woods and gets as far as Dunker Church, but then are stuck with no orders. 

Confederate dead near the Dunker Church

Union field command problem: McClellan has sent in two corps on the right wing, but has designated no field commander. At any rate, soon Hooker is wounded and carried off the field, and awhile later Mansfield is also mortally wounded at a critical juncture–and the individual brigades settle into just so many disconnected firefights with whichever Rebels are in front of them, having no orders to either advance or withdraw. The fight on the Federal right bogs down.

Part Two:
McClellan finally sends in Sumner’s II Corps. Gen. Edwin Sumner, the oldest general in the Army of the Potomac, advances directly westward, cutting across the front of battle, unsure even as to where his fellow Yankees are on the battlefield, so far. Part of Sumner’s men even open fire on their fellow Yankees in the murk of the East Woods.　

Mansfield and Sedgwick on the assault

Somehow, at about 9:00 AM, only Sedgwick’s division arrives, French and Richardson having drifted off to the left, and as this division crosses the front perpendicularly, the Rebels counterattack from the south, striking Sedgwick on the flank, and his formation breaks up. Meanwhile, farther away in the center of the field, French and Richardson deploy their divisions and advance on what appears to be a thinly-held line along a sunken wagon road. It is indeed thinly held, but the cover afforded by the sunken road allows D.H. Hill’s Confederates to shoot down large numbers of the French’s Federals as they advance over open ground. by 10:30 AM, within a mere hour of fighting, French’s division has lost 1,750 men out of 5,700. 


Sedgwick in the West Woods and fighting on the Bloody Lane

Then, Richardson’s division comes up, and renews the assault. Meagher’s famous Irish Brigade, green flags fluttering, makes a gallant assault and breaks the Rebel line for a time. Southern officers are falling, all of Hill’s brigade commanders being hit, and confusion reigns as orders are misunderstood. The Rebels are very thin, and a misunderstanding causes them to retreat. Lee, all this time, is desperately shifting reserves down to his center, to prevent a Yankee breakthrough. Richardson himself is mortally wounded, though, and the advance grinds to a halt. At this point, The Rebels here really have nothing left to resist a resumed Union advance. At this odd moment, Gen. Longstreet and his staff see the peril, and see nothing between them and the Yankee division but a battery of artillery, with most of the crews dead. Lonstreet, wearing carpet slippers, orders his staff to dismount and serve the guns, and they keep up a hot fire. D.H. Hill scrapes together a few stragglers and counterattacks. That–and getting a mortal would himself—convinces Richardson that they cannot push the attack. But for a while, it is clear that a big Federal push would win the day. McClellan feels he must hold on to his reserves and declines to send them in. Two entire Corps—the V Corps, under Porter, and Franklin’s VI Corps.

Part Three:Finally prodded into action by orders he does not receive until 10:00 AM, Gen. Burnside, still miffed over the slight he feels from McClellan’s assignments of command, begins to deploy his troops. He sends troops on several approaches to reach the Rohrbach Bridge (henceforth known as the Burnside Bridge). 

 
On the other side, entrenched in a ridge that dominates the bridge is Gen. Robert Toombs and his brigade–or, rather, part of it, since most of it had been summoned to assist elsewhere. All Toombs has left are two under-strength regiments, the 2^nd and 20^th Georgia, numbering 400 men plus—only this to face Burnside’s 12,500 men. But this position gives the Georgians a clear field of fire that sweeps down the length of the bridge, and they shoot down nearly every unit coming across. The bridge is littered with dead and dying Federals. Assaulting troops have to run down the ridge, run along the road parallel to the creek, and then dash across in column. Burnside ignores the fact that the creek is fordable, and sends wave after wave to take the bridge. Finally, Ferrero’s brigade, notably the 51^st New York and the 51^st Pennsylvania, make a desperate dash across the bridge, using a more direct route downhill, and they drive off Toombs and his men. Capt. William J. Bolton of the 51^st Penn writes of this assault which begins about 12:30 PM: . . . marching as if on regimental drill an sight never to be forgotten by those in that charge, gained the top of the hill overlooking the bridge and in full view. From that moment the regiment received volley after volley of grape, muysktery, shot, and shell, filling our faces and eyes with sand and dirt, all this time reserving our fire. . . . and after the regiment had cleared the fence that intervened between us and the bridge, the order to charge was given by [Colonel] Hartranft, certain death, as it were staring us in the face. We made the dash for the bridge through a perfect hell of shot and shell. . . . all this time the men falling all around, but in a few momnets we commanded the entrance to the bridge. . . . and in less than nine minutes the brigde and the heights beyond were in our possession and beyond dispute. . . . Within the few feet of the bridge a minie ball came crashing through my right lower jaw bone carrying away all the teeth on the right side of my face, both upper and lower jaw, passed through my mouth, and came out on the other side of my face. . . .
The 51^st Penn loses 135 men in that attack. 


Burnside gains the bridge until Hill counterattacks

Now that the bridge has been gained, Burnside takes another two hours before organizing a force to cross it and deploy on the far side to attack Lee’s right flank. In the meantime, he has sent Gen. Rodman’s division downstream to cross at a more fordable place. He moved his corps across the bridge slowly, and then found that he needed to bring up more ammunition. Finally, by 3:00 PM, Burnside is ready to attack Gen. D. R. Jones’s threadbare division. The Union assault is successful, and Jones pulls back. His line is about to break, and dust on the road and cheers announce the arrival of A.P. Hill’s division from Harper’s Ferry in the nick of time. Hill has lost half of his strength due to straggling, but he attacks Burnside anyway with about 3,000 troops on the Yankee left flank. This blow stops Burnside cold, who is now convinced that he cannot resume the assault. In one more push, he could have turned the flank and captured Lee’s only escape route.

The battle is over, and Hill’s’ counterattack has saved the Confederates from complete destruction. Union Victory.

Losses:            Killed    Wounded    Captured or Missing       Total

Union                2,108       9,540                     753                            12,401

Confederate    1,546       7,752                  1,108                            10,406

The Army of the Potomac has lost over 25% of those engaged in battle, and the Army of Northern Virginia loses over 33% of its strength present.


—Rebel artilleryman George Michael Neese, in reserve three miles away, describes the battle’s sounds:

At times the artillery fire was so fierce and heavy that it sounded like one continual roar of thunder rumbling and rolling across the sky. The musketry fire was equally severe and raged furiously, almost incessantly all day, and its hideous deathly crash vied with the deafening roar of the thundering artillery. It is utterly incomprehensible and perfectly inconceivable how mortal men can stand and live under such an infantry fire as I heard to-day. Judging from the way the musketry roared the whole surrounding air between the lines must have been thick with flying lead.

—Battle of Munfordville, Kentucky: Nearly 4,000 men under Col. Wilder surrender to Gen. Bragg’s Confederates.