CHAPTER 9

THE BATTLES OF SOUTH MOUNTAIN

SEPTEMBER 14, 1862

THE ARMIES FOUGHT THREE BATTLES ON SEPTEMBER 14. EACH was tactically separate from the rest, but they were, in effect, phases of a single far-flung engagement in which Lee resisted McClellan’s attempt to exploit the opportunity created by the finding of the Lost Order.¹

The long, rugged ridge of South Mountain separated the opposing armies. It could be crossed by troops with artillery at two points. The northernmost was Turner’s Gap, where the National Road linking Frederick with Boonsboro crossed the mountain; and adjacent to Turner’s were smaller gaps crossed by country roads, the most important being Fox’s Gap, one mile south. McClellan’s main force would follow this route to confront Lee’s detachment of the Army of Northern Virginia. Twelve miles south as the crow flies, but almost twice that by road, was Crampton’s Gap, where another road crossed the mountain into Pleasant Valley. For an army north of the Potomac this offered the most direct route to Maryland Heights, and it was the route by which VI Corps was marching to effect the relief of Harpers Ferry.

At Harpers Ferry itself, the morning of the fourteenth saw the Confederates completing their encirclement of the garrison. Walker’s Division (five thousand) occupied Loudon Heights, southeast of town on the far side of the Shenandoah River. McLaws’s command was in possession of Maryland Heights on the north bank of the Potomac, and his men were swinging axes and shovels to hack a path for their artillery through the woody thickets along the ridgeline of Elk Mountain. When their guns were in position they would be able to sweep every part of the Union lines. Jackson’s command (twenty thousand) was completing its march from Martinsburg, emerging from the hills and marching across the open ground in front of Bolivar Heights south of the town. Although every element necessary to force the surrender of the post was on the scene, it would take Jackson all day to put his forces in position to make victory certain. His troops had to deploy and begin its advance against Bolivar Heights, working itself forward to a position close enough to allow Jackson’s artillery to support an infantry assault. A. P. Hill’s Light Division would have to push its way through the woods along the Shenandoah River, seeking a position from which it could assail Bolivar Heights from the flank. Jackson was also having great difficulty establishing effective communication with the commands of Walker and McLaws. The peculiar terrain around Harpers Ferry, which had made it necessary for the three columns to move independently, made it impossible for them to establish direct contact. Walker was separated from Jackson by the Shenandoah River and the open country at the foot of Loudon Heights. McLaws was cut off from both Jackson and Walker by the Potomac River—the only bridge in his sector led straight to the Union lines at Harpers Ferry.

McLaws was almost completely isolated, in a position vulnerable to attack by Federal forces moving through Crampton’s Gap. His communication with Jackson was tenuous. There was no physical contact between the commands and they could only communicate by using signal flags. Lee could offer him no material aid, and although he sent several dispatches offering advice, he would not give McLaws any orders. McLaws had been apprised of the danger from Crampton’s Gap, but he was deeply absorbed in his primary mission of bringing his artillery onto Maryland Heights. He had sent only two small infantry brigades to hold Crampton’s Gap, and they had been joined during the night by two brigades of Stuart’s cavalry that had ridden down from Turner’s Gap.

TURNER’S GAP, DAWN TO 2:00 PM

Lee’s immediate concern on September 14 was to prevent McClellan from smashing through D. H. Hill’s Division at Turner’s Gap and striking Longstreet’s Divisions before they could be concentrated for the defense of Boonsboro. If that defense failed he would have to make a hasty retreat to Virginia, to save his army’s supply train and artillery reserve and prevent the destruction of Longstreet’s divisions.

Although McClellan credited Lee with fifty thousand troops concentrated at Boonsboro, he probably had fewer than half that number. Longstreet’s and D. H. Hill’s commands might have mustered twenty-six thousand men at the start of the campaign, but by the fourteenth, straggling had reduced their strength dramatically. Hill had no more than eight thousand of all arms, Longstreet fifteen thousand or fewer because he had to detach several regiments to guard the army’s trains and artillery as they withdrew toward Williamsport. Moreover, on the morning of September 14 the elements of the defending force were still divided. Longstreet’s troops had been marching all night from Hagers­town and would have to make a forced march from Boonsboro to reach the gaps by 1:00PM, losing strength to straggling as they came. Three of Hill’s brigades had bivouacked near Boonsboro and would not reach Turner’s Gap until noon. At daybreak on the fourteenth the only forces in place to defend the gaps were two brigades of Hill’s Division and a single cavalry regiment, about 2,300 men. They faced an immediate assault by the infantry of Cox’s Kanawha Division and Pleasonton’s cavalry, about 8,000 strong. Fortunately for Hill, the Union IX Corps would not break camp until 10:30 AM, and its infantry would not begin to arrive until noon, by which time the rest of Hill’s units would be at hand and Longstreet’s troops would be approaching the gaps from the west. ­Hooker’s Corps had a much longer march—fourteen miles from Monocacy Junction—and would not reach the field until well after noon.

Major General Daniel H. Hill was noted equally for his piety and a sarcastic manner that did not endear him to his superiors. He was forty years old, West Point Class of 1842; had distinguished himself in combat during the Mexican War, then resigned his commission in 1849 to teach mathematics at Washington College, Davidson College, and the North Carolina Military Institute. As a colonel of North Carolina troops in June 1861 he had won the first post-Sumter skirmish of the war, at Big Bethel, Virginia, and was immediately promoted to brigadier general. He was promoted to major general during the Peninsula campaign, where he proved to be one of the abler division commanders. Though his difficult personality would eventually lead Lee to transfer him out of the Army of Northern Virginia, both Lee and Longstreet thought he had the tactical skill and aggressive instincts needed for the desperate defense of Turner’s Gap.

The main route through Turner’s Gap was easy to defend. At the crest, the National Road ran through a narrow passage between high, wooded hills. With fieldworks across the low ground and riflemen on the slopes, Colquitt’s Brigade of about 1,000 infantry and a battery could hold its ground against a much larger force. However, one mile north and one mile south of Turner’s there were other gaps, reached by roads branching off the National Road. Fox’s Gap to the south was the larger of these, a saddle half a mile wide, separated from Turner’s Gap by a steep wooded ridge. There was another, smaller set of gaps to the north, but the terrain there was more rugged and heavily wooded, and the gaps harder to approach. D. H. Hill lacked the strength to cover all three gaps, so he used his lone cavalry regiment to screen the northern gap and sent Brigadier General Samuel Garland’s Brigade to cover Fox’s Gap.

Federal General Jacob Cox brought his Kanawha Division forward early in the morning, assessed the strength of the Turner’s Gap position, and decided to turn it by striking through Fox’s Gap. His lead brigade, three thousand men with an artillery battery, peeled off the National Road and trudged up through the woods to the cleared ground at the top of the pass. Among the regiments led by brigade commander Colonel Eliakim Scammon was the Twenty-third Ohio, commanded by Lieutenant Colonel Rutherford B. Hayes, which included a platoon led by Sergeant William McKinley. Hayes would be wounded that day, McKinley would pass unscathed, but both would survive to be elected president of the United States.

Scammon made contact with Garland’s line and deployed his brigade into line. He outnumbered Garland three to one. The Federals opened up with shell fire and musketry, then advanced in a line that outflanked Garland left and right. The Twelfth North Carolina, a rookie regiment, broke and ran, and Garland was killed trying to hold the rest of the brigade together. By 10:00 AM Fox’s Gap had been cleared.

Cox might have been able to drive the rest of D. H. Hill’s troops off South Mountain if he had followed up this success. His second brigade, commanded by Colonel George Crook, was right behind Scammon’s. It could have passed through, swung to the right, taken the defenders of Turner’s Gap in the rear, and forced them to retreat. However, Cox did not know what kind of strength the Rebels had on his front. Heavy rifle fire from skirmishers in the woods ahead suggested the presence of a large force. Cox was also far in advance of the rest of IX Corps, isolated for the moment and without support. He therefore decided to hold until the rest of IX Corps came up.

Brigadier General Jesse Reno was in command of IX Corps. He did not have the proper rank for corps command but was an experienced officer who had commanded two divisions of the corps at Second Bull Run. His orders were now coming from General Burnside, who had been commanding IX and I Corps as a “wing” of the army since September 7. Burnside delayed Reno’s advance until midmorning to allow I Corps to close up. It was not until 10:30 AM that IX Corps broke camp and began its march up the National Road, with Willcox’s Division in the lead followed by the divisions of Sturgis and Rodman. Perhaps an hour behind Rodman were the advance elements of I Corps, which had marched at daybreak from its encampment south of Frederick.

As the day’s fighting began, McClellan was still at his headquarters in Frederick, more than fifteen miles from Turner’s Gap. At 9:00 AM Captain Russell, the messenger sent by Colonel Miles, reached him after an all-night ride, with the warning that Harpers Ferry would only be able to hold out for one more day. McClellan sent three couriers to carry his reply, urging Miles to hold out to the last extremity and assuring him relief was on the way. However, McClellan did not pass Miles’s warning to Franklin or enjoin him to meet the emergency by moving faster and striking harder. And none of his messengers got through to Miles. McClellan then mounted up and rode forward to confer with Burnside, whose field headquarters were just off the National Road where it begins its rise toward Turner’s Gap. General Reno’s IX Corps headquarters were probably nearby.

The day was hot, temperature only in the midseventies but the air humid and heavy. Federal soldiers wore uniforms of blue wool, more durable than Southern homespun, but heavier and hotter, especially on a day when high humidity stifled the evaporation of sweat. All the corps in the northern axis of advance were queued up along a single highway, the National Road that ran from Frederick to Boonsboro. This slowed the pace of their advance and deployment. Every brigade had to wait for the one ahead of it to deploy before it could follow and go into action. They were also hindered by the terrain, which was hilly and covered with woods and thickets. The Confederates complicated things by the active use of skirmishers—small parties of riflemen spread out in advance of their main line—not only in Fox’s Gap but on the hillside north of the National Road as well, where a lone cavalry regiment disputed the paths by which troops could circle behind the Turner’s Gap defenses.

At noon General Orlando Willcox’s Division arrived at IX Corps headquarters. Reno ordered the division to leave the National Road and go to Cox’s support in Fox’s Gap. Willcox’s two brigades followed the rough path that Cox’s Division had used earlier, but before they reached the gap they had to leave the path and move through the woods to take position at the right of Cox’s line, and that disrupted their organization and slowed their movement.

At the same time, on the Confederate side the remaining three brigades of D. H. Hill’s Division had finally reached Turner’s Gap after a six-mile hike from Boonsboro. Hill had only Colquitt’s Brigade blocking the main road through Turner’s Gap, but its position at the narrowest point of the gap was extremely strong. Hill sent Rodes’s Brigade to defend the small gaps one mile north of Turner’s, which had been thinly held by a single regiment of cavalry. The other two brigades were sent through the woods to the south, with orders to attack and drive the Federals out of Fox’s Gap. Brigadier General Roswell Ripley, who was to lead the attack, had just reached the scene and was unfamiliar with the Federal positions and blinded by the woods. The attack he ordered was disjointed, some units getting in among the Union lines and taking heavy losses while others failed even to find the enemy. Cox’s and Willcox’s troops easily beat back the assault.

However, the noise of that failed Confederate attack was heard at headquarters, and made Burnside worry that more strength was needed to drive through Fox’s Gap. At about 2:00 PM Burnside sent Reno with the rest of IX Corps up the narrow track to prepare a heavy offensive, just as Hooker’s lead elements came marching up after a long hike from Frederick. The I Corps troops roused at the sight of McClellan himself, sitting his big black horse by the roadside as they hit the upslope to Turner’s Gap. McClellan turned the moment into grand theater, with himself as the central figure—not merely a hero but an object of worship. A Massachusetts soldier remembered:

It seemed as if an intermission had been declared in order that a reception might be tendered to the commander-in-chief. A great crowd continually surrounded him, and the most extravagant demonstrations were indulged in. Hundreds even hugged the horse’s legs and caressed his head and mane. While the troops were thus surging by, the general continually pointed his finger to the gap . . . through which our path lay. It was like a great scene in a play, with the roar of the guns for an accompaniment.²

Burnside, with McClellan’s advice, would direct the battle for the gaps. IX Corps would soon be heavily engaged on the left at Fox’s Gap. A direct attack up the National Road was inadvisable, because the narrowness of the pass would constrict the Federal battle line and funnel it right into the guns of the defenders. Burnside therefore ordered Hooker to swing most of his corps off to the right, and advance through the woods to another smaller pass that broke the ridgeline a mile or so north of Turner’s Gap. The Confederates would have to stretch out their defenses to block IX Corps at Fox’s Gap and Hooker’s I Corps at the northern gap. The strength of their battle line would be attenuated, and it would break when I and IX Corps attacked in concert.

The difficulty of moving through mountainous and heavily forested terrain meant that these Federal maneuvers took a great deal of time. If Burnside had not waited for Hooker but had attacked with IX Corps alone between noon and 2: PM, he might well have driven D. H. Hill’s outnumbered brigades out of the gaps. After the rout of Garland’s Brigade, Hill had fewer than seven thousand troops facing about fifteen thousand Federals. But it was extraordinarily difficult for Burnside’s officers to establish the strength of the enemy in their front, because of the heavy woods and the Rebels’ effective use of skirmishers. Caution was justified by the best available intelligence, which indicated that half of Lee’s army was no farther off than Boonsboro and might well have moved eastward in the days since the lost order was issued.

But the delay in the Federal attack insured the result they feared. At 2:00 PM the last of D. H. Hill’s brigades reached Turner’s Gap. Behind them were Longstreet’s divisions, turning onto the National Road after a fourteen-mile march from Boonsboro. Despite his splinted arms, General Lee mounted his horse and had his aide lead him to the roadside to encourage the troops by his presence. Drayton’s Division passed, followed by the division of Brigadier General John Bell Hood.

Hood had earned a reputation as the hardest-hitting offensive general in the Army of Northern Virginia. West Point–trained, tall, blond and powerfully built, his reputedly handsome features were masked by a full beard that reached to his chest. The slight downward droop of his fierce eyes gave him the look of a mournful lion. He had made his name at Gaines’ Mill at the start of the Seven Days, when he led his Texas Brigade in a bayonet charge that broke the Union center and forced Porter’s V Corps to begin the retreat that would end at Harrison’s Landing. From that day “Hood’s Texas Brigade” were rated the shock troops of the army, a reputation they vindicated at Second Bull Run when they led the charge that broke Pope’s flank. They were westerners in an eastern army—and Texans to boot—frontiersmen bearing the pride of their section among strangers in the metropolis. This day Hood himself was in arrest for a minor breach of discipline. As his old Texas Brigade passed the men called out to Lee, “Give us Hood!” Lee answered, “You shall have him,” and released the general from arrest in time for Hood to lead his men into action.

Though Longstreet was now the senior general on the scene, he left direction of the field to D. H. Hill, who was more familiar with the terrain and troop deployments. Hill had sent Rodes’s Division to defend the gaps north of Turner’s against Hooker’s impending assault. He split Drayton’s Division as it came up, sending half south to Fox’s Gap and the rest to join Rodes; then did the same with Hood’s Division, sending two of his brigades to Fox’s Gap and the third to the northern flank. It would be close to 4:00 PM when they arrived, just ahead of the Federal attack.

CRAMPTON’S GAP, DAWN TO 4:00 PM

McClellan had ordered General Franklin to march at dawn on the fourteenth, break through Crampton’s Gap, and relieve Harpers Ferry. Franklin’s Corps was roused early in the morning and took the road at about the time Cox was making his first attack at Fox’s Gap. The VI Corps had fourteen miles to march before it reached Burkittsville, at the base of the Crampton’s Gap road. Slocum’s division led the march and did not reach the town till noon. Yet by one of those ironies characteristic of the Antietam campaign, the delay actually improved Franklin’s odds of achieving his objective.

Jeb Stuart had concentrated all but one of his available cavalry units at Crampton’s Gap, on the correct assumption that a Federal drive against McLaws’s rear posed the most significant danger to Confederate operations. As a result, he was confused and concerned to see the morning pass without any sign of a Federal offensive toward Burkittsville. Stuart assumed that Union forces were using a different route to effect the relief of Harpers Ferry: most likely the twisting road and railroad right-of-way that followed the north bank of the Potomac—eight miles south by air line, twice that far by road. Stuart therefore withdrew Hampton’s Brigade, the largest component of his force, back through Crampton’s Gap into Pleasant Valley, then rode south to the river road. He left behind a half-strength brigade to aid the two infantry brigades stationed in the gap by McLaws. Stuart told McLaws what he was doing, and in the late morning McLaws ordered an additional brigade to join the defense at the gap—“Cobb’s Legion,” another under-strength unit, which had been raised and was commanded by Brigadier General Howell Cobb, a former U. S. Treasury Secretary and one of the Confederacy’s Founding Fathers. Then McLaws returned to his main task, trying to speed the placement of artillery on Maryland Heights to support Jackson’s attack.

Slocum’s Federal division arrived at Burkittsville at noon and found the town lightly held by Confederate infantry. The division deployed a heavy skirmish line and advanced, and the Rebels retreated into the gap. Slocum followed them cautiously, since he did not know the strength of the enemy ahead of him. Franklin’s second division under General William “Baldy” Smith was some distance behind Slocum, and Franklin held it back as a reserve. Couch’s Division had been camped far to the rear of the other divisions, and Franklin seems not to have had any idea when it might catch up. That left him with only two divisions, thirteen thousand troops, to face whatever force Lee and Jackson might have behind South Mountain. He had no way of knowing whether any of Longstreet’s men had come south to block Crampton’s Gap; nor did he know what was happening at Harpers Ferry, and whether some, most, or all of McLaws’s command was waiting for him.

It was 2:00 PM when Slocum’s division finally reached the top of Crampton’s Gap. At the same time, twelve miles north, Burnside’s IX and I Corps were just beginning to move into position for their assault against three Confederate divisions. Slocum had about 7,000 troops facing no more than 2,200 Confederates, and Slocum was an experienced combat leader who knew the value of prompt and energetic movement. He deployed his division in line of battle overlapping the Confederates on both flanks, raked their position with artillery, then sent the infantry forward. The Confederate regiments tried to stand their ground but they were outflanked and overwhelmed. After a short and sharp struggle, they broke down from the gap into Pleasant Valley, with Slocum’s Brigades on their heels. The fugitives met Cobb’s Legion on the road, and tried to rally around them, but this line, too, was outflanked and driven back to Elk Mountain. McLaws got word of the disaster and pulled as many units as he could spare off Maryland Heights and formed them for defense at the northern end of the ridge. Slocum had lost 531 men, the Confederates about 900, half of them prisoners.³

Two hours after Slocum’s attack Franklin had two divisions in firm possession of Crampton’s Gap and three hours of daylight in which to use them. Baldy Smith’s Division had not had to fight that day, and Slocum’s Division was probably fit for further service. Franklin’s orders called for him to turn south and strike for Maryland Heights, but he was also to keep an eye out to the north. Opportunity might beckon there, to strike the Lee-Longstreet force in its southern flank; but if Lee was able to send aid to McLaws it would come from the north, and hit Franklin from the rear if he turned south. Franklin was out on a limb, uncertain of McLaws’s strength and of Lee’s intentions. Couch’s Division had not yet caught up. No advice came from McClellan. So instead of advancing, Franklin consolidated his defenses in the pass and waited for Couch to come up.

Historians of the campaign have criticized Franklin for not trying to complete his mission to relieve Harpers Ferry on September 14. However, it is unlikely that a continued offensive by the two divisions he had on hand would have broken through McLaws’s defense on Elk Mountain and reached Harpers Ferry in time to prevent its surrender. There were only three hours of daylight remaining. Both of Franklin’s divisions had made a long march that day, and Slocum’s men had fought a wearing battle. The ridged and wooded terrain of Elk Mountain would have slowed even an unopposed advance along its eight-mile length, and McLaws had five thousand infantry in line to defend it.

But if the chances of an actual breakthrough were doubtful, the sounds of a continued offensive might have told Harpers Ferry that help was near, and encouraged the garrison commanders to make a stronger defense.

HARPERS FERRY, 2:00 TO DUSK

All that day, while the troops of Longstreet, D. H. Hill, and McLaws struggled to hold the South Mountain gaps, Jackson’s Corps was completing its approach to Bolivar Heights, pushing twenty thousand infantry forward to cover the emplacement of artillery. The menace of its inexorable advance was augmented by the gunfire from Walker’s Division on Loudon Heights and McLaws’s gunners on Maryland Heights, which raked the town’s defenses and the rear of the Bolivar Heights line.

In front of Bolivar Heights, Jackson’s infantry established advanced positions right up against the thick abatis that protected the Federal line—a barrier of interlocked brush and small trees. At the same time Archer’s Brigade of A. P. Hill’s Division had worked down through the woods along the Shenandoah River and lined itself up to hit Bolivar Heights from the flank. However, before the infantry could storm the Heights, engineers would have to cut paths through the abatis, while the artillery would have to beat down the defenders’ guns. The result was that no infantry attack could be mounted until the following day, September 15, three full days after the date Lee had expected Harpers Ferry to be in his hands.

Nevertheless, the positions attained by Jackson’s infantry and artillery made the defense of Harpers Ferry absolutely hopeless. Bolivar Heights was the only high ground from which the town could be defended, and Jackson’s troops and guns would be able to hit it front, flank, and rear at first light. At nightfall Jackson sent a courier to Lee: “Through God’s blessing, the advance, which commenced this evening, has been successful thus far, and I look to Him for complete success to-morrow.”⁴

TURNER’S GAP, 4:00 PM TO DARK

The Federal assault on D. H. Hill’s attenuated line began at 4:00 PM, just as Franklin’s assault at Crampton’s Gap was winding down. Hooker’s I Corps was in position on the right, ready to attack the northern flank of the Confederate line. If he could break that line or even throw it back, his corps could threaten or cut the National Road and compel the Confederates to retreat from South Mountain in great haste. Hooker maneuvered his divisions effectively, forcing Hill to spread his units more thinly. Then, at the given word, the corps’ three divisions surged forward, thirteen thousand infantry against about half that many Confederates.

Simultaneously, over on the Union left, Brigadier General Jesse Reno led the IX Corps in a frontal assault against the Fox’s Gap line. The Federals, crossing open ground, ecountered stubborn resistance as Confederate Brigadier General John Bell Hood aided the defense with two veteran brigades and his own superb skill as a combat commander. Reno’s battle lines struggled uphill against heavy fire, and Reno himself was shot from his horse with a mortal wound. Cox of the Kanawha Division was the senior officer on the scene, and he assumed command despite the fact that his division had only recently, and provisionally, been assigned to the corps. The fighting here became a furious extended stalemate, battle lines so broken by woods and thickets that command and control was problematic. Individual Union and Confederate regiments staged lone-wolf attacks, thinking to seize some local advantage, only to be cut off and cut up and driven back.

Hooker made much better progress on the right. By 5:20 PM Brigadier General Randolph Marcy, McClellan’s chief of staff, reported opposition melting away in front of I Corps. Even so, it was impossible for the victorious Federals to simply sweep through the northern gaps and cut the National Road. Pockets of resistance and the rocky thickety terrain made an organized advance difficult. As the sun sank, General Burnside thought a new assault was needed to finally break the Rebel line. He ordered Brigadier General John Gibbon’s “Iron Brigade” to charge straight up the National Road and storm the defensive position where Colquitt’s Brigade had been dug in for two days.

Gibbon’s brigade had seen its first combat only two weeks before, but it had already earned a reputation as one of the best fighting commands in the army. Gibbon was Philadelphia-born but raised in North Carolina, an 1847 graduate of West Point who had missed seeing action in the Mexican War and spent fifteen years in the thankless task of commanding artillery units in the peacetime army. He had fought his battery well at First Bull Run, won his general’s stars and command of four rookie regiments, the Second, Sixth, and Seventh Wisconsin and the Nineteenth Indiana, to which his own Regular Army artillery battery was added. Western troops were reputed to be undisciplined, but Gibbon had the right touch and the men were apt pupils. Like Hood’s Texas Brigade on the Confederate side, the Iron Brigade were westerners in an eastern army and felt they had something to prove about the soldierly virtues of people in their part of the country. They marked their difference by wearing, instead of the standard issue kepi, a distinctive bell-crowned black hat, one brim pinned up with a black cockade—an assertion of pride, which made them conspicuous while they strove to justify the assertion. The brigade’s baptism of fire had come against Stonewall Jackson’s troops less than a month before, in the prelude to Second Bull Run. In that first fight, and in the army’s disastrous defeat on August 29–30, the brigade had held its ground despite heavy casualties and the demoralization of the troops around it.

However, their present assignment was hopeless. They had to attack on a narrow front, straight into the rifles and artillery of well-entrenched Confederates. Their valor and skill only served to carry them closer to their goal than an average outfit would have got, at the cost of heavier losses—over 250 men. Unlike the average brigade, they were not demoralized by the setback but angry and eager to get even.

But the Iron Brigade’s attack was unnecessary. Hooker’s sweep had compromised the Confederate defensive line. At nightfall Lee ordered D. H. Hill and Longstreet to pull their men off South Mountain that night and form them up for a retreat.

THE RESISTANCE OF LONGSTREET’S and D. H. Hill’s divisions had succeeded in delaying the advance of McClellan’s main force for one full day, inflicting 1,800 casualties in the process. By keeping Union troops at bay until nightfall, they had contributed to the uncertainty that had led Franklin to halt his advance at Crampton’s Gap and postpone his advance to relieve Harpers Ferry till next morning.

However, Lee had no knowledge of what was happening at Crampton’s Gap or at Harpers Ferry. He only knew that the northern wing of his army had suffered a serious defeat, and he was doubtful whether it could stave off a determined advance by McClellan’s much larger force. The Confederates had 2,300 troops either killed, wounded, or missing, and many other men had straggled on the way to the fight or been separated from their units during the battle. The three divisions in this part of Lee’s army would not be fit to stand and fight for a day or so, which meant they could not make more than a token stand at Boonsboro. Lee feared that if Franklin was advancing against McLaws with the same energy and force McClellan had shown at Turner’s Gap, McLaws’s hold on Maryland Heights would be compromised, and the siege of Har­pers Ferry doomed to failure. In these circumstances, he thought it was imperative to save McLaws’s command from being surrounded and destroyed. So at 8:00 PM (and again at 11:15), Lee sent orders for McLaws to withdraw his command northward to Sharpsburg, where it would join the troops retreating from Turner’s Gap.⁵

It seemed evident to Lee that the Maryland campaign had failed, and that the forces north of the Potomac would have to retreat to Virginia to reunite with Jackson’s command in the northern Shenandoah Valley. The army’s wagon train and reserve artillery were already crossing the Potomac near Williamsport, which was more than fifteen miles west of Boonsboro, but Lee was concerned enough about their safety to send part of Georgia Brigade for additional protection. The units defeated at Turner’s Gap were stumbling down the road to Boonsboro in the dark. Walking wounded mixed with files of weary riflemen, and ambulances carrying stretcher cases were scattered through the marching columns, as were artillery batteries—guns, caissons, and limber chests. Regimental officers built campfires off the road and stood calling out their unit names, hoping to draw in companies that had become separated in the retreat through the woods.

Hood’s infantry was behind them as a rear guard, with Brigadier General Fitzhugh Lee’s newly arrived cavalry brigade watching the side road down from Fox’s Gap. All of these commands would fall back through Boonsboro to Sharpsburg, a small town on Antietam Creek that offered a short line of retreat across the Potomac to Virginia via Shepherdstown and Boteler’s Ford.

HARPERS FERRY, NIGHT

Inside Harpers Ferry, Colonel Miles and General White accepted the hopelessness of their situation. The military code of honor, and the common practice of Civil War armies, did not require Miles to fight to the last like Travis at the Alamo. On the contrary, commanders trapped in an obviously indefensible position were expected to surrender to avoid “the useless effusion of blood.” Miles was obliged to wait until Jackson opened fire and formed his troops for the assault, but once Jackson had demonstrated his readiness to storm Bolivar Heights, Miles was free to send out the white flag.

One of Miles’s subordinates was unwilling to go along with the program. Colonel Benjamin “Grimes” Davis, commanding the Eighth New York cavalry, wanted to break out and save his command from capture, and after dark he went to Colonel Miles’s headquarters in town to ask for permission. Miles refused, insisting he needed every man for the defense, despite the obvious fact that he intended to surrender the next day. Davis had his own ideas of duty and honor, and the courage to back them against any opposition. He was a veteran Indian fighter, thirty years old, Alabama-born and Mississippi-raised, the only West Pointer from the Deep South to reject the claims of kin and section and stay with Old Flag. He told Miles he saw neither honor nor military use in surrendering his outfit, when it could readily escape the trap and rejoin the main army for its impending showdown with the Rebels. Davis put his case in terms strong enough to provoke a heated argument, which he ended by informing Miles that no matter what the post commander said, he was going. Miles gave in.⁶

The argument was overheard by the commanders of the other cavalry units in camp, who decided to join his attempt at a breakout. After dark, Davis led about 1,300 troopers over the pontoon bridge below Maryland Heights, the planking covered with hay to muffle the clump of hooves. Local guides directed the horsemen onto a winding path through the woods that followed the river under the western scarp of the Heights. Davis was prepared to cut his way through with saber and pistol, but McLaws had only a small infantry squad guarding this road. Davis’s advance guard captured it, and his command rode on unmolested.

About ten miles north of their crossing, the flatlands of the Antietam Creek valley opened out on their left. They crossed the creek and picked their way north along country lanes that skirted the town of Sharpsburg. In the dark, Confederate troops and wagon trains were moving in bunches here and there along all the roads running down from Hagers­town in the north and Boonsboro to the northeast. With skill and luck, Davis’s pickup brigade avoided colliding with any of these units as it rode north. Davis reckoned that all of Lee’s army was between him and McClellan’s forces on the far side of South Mountain, so he kept riding north in order to pass around the Confederates’ northern flank. Just before first light, thirty-five miles from his crossing, he reached the road that ran between Hagerstown and the Williamsport fords—the road by which the wagon trains of Lee’s army were retreating from Hagerstown. Out of the predawn mist came a forty-wagon ordnance train bearing the ammunition reserves of Longstreet’s Corps. Davis hailed the lead wagons in fluent Alabaman and ordered them to follow him. He led them north while the Twelfth Illinois of his command held off the Confederate train guards, who belatedly discovered that their charges had gone astray. At 9:00 AM Davis brought his four regiments and the wagon train to safety in Greencastle, Pennsylvania. He reported his arrival to the governor of the state, who passed the message to Stanton: the wagons captured, but Harpers Ferry certain to surrender that morning.⁷