Robert E. Lee had few military options after the month-long Second Manassas Campaign, which drove Union general John Pope‘s Army of Virginia back upon the defenses of Washington, D.C. Even after successfully moving the war’s front lines from Richmond to Washington, Lee could not remain in northern Virginia because there was not food enough there to supply his army. Rather than retreat to central Virginia or seek the safety of the Shenandoah Valley, he instead marched his men north. Confederate troops under the command of Thomas J. “Stonewall” Jackson crossed the Potomac River at White’s Ford, in Loudoun County, and entered Maryland on September 4. It was one of the boldest decisions Lee ever made.
Describing his army as “not properly equipped for an invasion of an enemy’s territory,” Lee nevertheless counseled Confederate president Jefferson Davis—who worried about his capital’s security—that “we cannot afford to be idle” and that “as long as the army of the enemy are employed on this frontier I have no fears for the safety of Richmond.” Lee cited a number of reasons for the campaign. He hoped that Maryland, a slave state, would join the Confederacy. He also hoped to undermine Northern morale enough that in the autumn voters might elect a Congress intent on “peace at any price.” Recognizing that a move northward would force pursuing Union troops to evacuate Virginia, Lee hoped that the autumn harvest, especially in the Shenandoah Valley, would be available to sustain his army and the citizens of Virginia through the winter. These were reasons enough to overcome Lee’s reservation about his army’s lack of shoes, horses, and supplies.
Lee’s plan also exploited the fact that the Lincoln administration was in disarray, its armies demoralized and dispirited. After Pope’s loss at Second Manassas, Lincoln banished the general to Minnesota. The former general-in-chief George B. McClellan was discredited, too, following the Peninsula Campaign and the Seven Days’ Battles, when he was forced to retreat from the gates of Richmond. But Lincoln now turned to McClellan anyway, placing him in command of the capital’s defenses on September 2. He did so over the objections of most of his cabinet. On September 5 McClellan wrote, “Again I have been called upon to save the country.” On that same day Lincoln and Union general-in-chief Henry W. Halleck—having been rebuffed by two other generals—verbally offered him field command of the Army of the Potomac. Or so McClellan claimed. Lincoln later said that Halleck had made the offer, and Halleck pointed the finger at Lincoln.
The Campaign Begins
Lee entered Maryland with approximately 65,000 men, and by September 7, he had concentrated most of them in Frederick, a city just forty miles to the northwest of Washington, D.C. On the same day, under orders to protect Washington and Baltimore, and to drive the Confederates back across the Potomac, McClellan led a hastily organized force out of Washington. The Army of the Potomac comprised elements of three armies, assorted independent commands, and 18,000 new troops. Hampered by poor logistical support and a lack of accurate intelligence reports, McClellan moved cautiously. At Frederick, Lee had positioned himself at a crossroads, with access to both Washington and Baltimore. In order to defend these cities, McClellan was forced to spread his men all the way from the Potomac River to Baltimore.
On September 8, while in Frederick, Lee issued a “Proclamation to the People of Maryland,” declaring that his campaign would free Marylanders to join the Confederacy. Lee’s private letters to Davis reveal that he did not truly expect Maryland to secede, but the proclamation nevertheless provided a convenient justification for his army’s occupation of Union soil. After issuing strict orders prohibiting his men from pillaging, Lee wrote to Davis urging the Confederate president to open negotiations with the Union government over recognition of Confederate independence. Assuming that his campaign would demoralize the Northern public and influence the autumn midterm elections, and with Confederate offensive operations occurring all the way west to the Mississippi River Valley, Lee thought the war might be won within a few weeks.
In the meantime, Lee recognized a threat to his supply line and took immediate action to secure it. The Confederate army’s food, clothing, weapons, and ammunition had been transported out of the main supply depot at Culpeper via the Virginia Central Railroad, but during the Second Manassas Campaign, Pope had destroyed many of the railroad’s bridges, forcing Lee to funnel his supplies north on horse-drawn wagons. Now that the Confederates had moved into Maryland, the supply line not only became extended, but swung dangerously close to Washington. Lee thus determined to move his main depot to Winchester, in the lower, or northern, Shenandoah Valley. Standing between the depot and Lee’s hungry men, however, was Harpers Ferry, occupied by Union troops since the frantic first months of the war. The Union department commander, John E. Wool, ordered that those men should remain in place.
The Lost Order
On September 9, Lee conceived of an elaborate plan to deal with this turn of events. While the rest of Lee’s men headed north to Boonsboro, Stonewall Jackson would march about two-thirds of the Confederate army back across the Potomac to quickly capture Harpers Ferry. It was a risky move because, in dividing his army, Lee would make the Confederates particularly vulnerable to attack. In fact, Lee divided his army not into two parts but four. He ordered Jackson to separate his men into three columns, each charged with capturing various points of high ground above Harpers Ferry. Once the garrison had surrendered, and Jackson and Lee had reunited, they would then continue north to another crossroads, at Hagerstown, Maryland. From there the Confederates would be able to move in several directions, forcing Union pursuers to disperse their strength while allowing Lee to again concentrate his.
Lee’s plan found official expression in Special Orders No. 191, duplicates of which were distributed to various subordinates. Lee addressed one of these copies to Confederate general Daniel Harvey Hill. Jackson also sent Hill a copy, and after the war, Hill produced the order from Jackson. The one from Lee, however, was lost in the vicinity of Frederick.
In the meantime, McClellan lacked solid evidence of the Confederate army’s size and the direction of its movements, and he thus continued to advance on a broad front in order to defend both Washington and Baltimore. While pushing toward Frederick, his army covering each of the three main roads, McClellan received widely varied estimates of Lee’s intentions and numbers. His best guess, based on cavalry and civilian reports, put Confederate strength at about 100,000 men, or not quite double the size of Lee’s actual force. McClellan based his operations on this figure, leading him to move with what later historians criticized as too much caution.
Pursuant to Special Orders No. 191, Jackson marched his men toward Harpers Ferry on September 10. Jackson himself swung one arm of his force wide to the west, so that it fell on another Union garrison at Martinsburg before approaching Harpers Ferry from the west. Confederate general John Walker moved to the south, re-crossing the Potomac River and occupying Loudoun Heights, to the south of Harpers Ferry. Lafayette McLaws commanded the third arm of Jackson’s force. He took a more or less direct route to Harpers Ferry, marching to the southwest across South Mountain to Maryland Heights, to the north of the Union garrison.
While Jackson pursued his prize at Harpers Ferry, the rest of the Army of Northern Virginia marched north to Hagerstown. This happened sooner than Lee had originally outlined, but the general had heard that Union troops might be approaching Hagerstown from the north, and he determined that the town was crucial to his operation. D. H. Hill’s men brought up the Confederate rear, leaving Frederick on September 11.
McClellan drove the last Confederates out of Frederick and entered the city on September 12. The next day, in a meadow outside the city, Corporal Barton W. Mitchell of the 27th Indiana found a copy of Lee’s Special Orders No. 191 wrapped around a few cigars. The document—which came to be known as the Lost Order—was quickly passed on to McClellan, who ordered a reconnaissance to confirm its veracity. By this time Jackson’s forces had surrounded the Union garrison at Harpers Ferry and were conducting a siege of the town.
On September 12, the Army of Northern Virginia was dangerously spread across roughly twenty-one miles, from Harpers Ferry north to Hagerstown. Providing the only link between Jackson in the south and James Longstreet‘s men to the north, D. H. Hill’s division was then at Boonsboro, near South Mountain. The town was situated about halfway between Frederick and Hagerstown, and about halfway between Hagerstown and Harpers Ferry. McClellan was jubilant. On September 13 he sent a telegram to Lincoln: “I have the whole rebel force in front of me … I think Lee has made a gross mistake, and that he will be severely punished for it.”
His jubilation was tempered with caution, however, as the Lost Order appeared to confirm his belief in Lee’s superior numbers. After listing the various divisions detached with Jackson, the order twice referred to the “main body” of the army, suggesting that Lee commanded a force so large he did not fear dividing it in enemy territory. If the order called attention to the challenges in confronting Lee’s army, it also demanded action. Already having ordered his men to move in the direction of South Mountain, McClellan now understood that an attack there would divide the Confederates, rescue the Harpers Ferry garrison, and perhaps allow him to destroy Lee’s army piece by piece.
On the evening of September 13, Lee hastily ordered Hill to block the roads that traveled over South Mountain, hoping to buy time while Jackson continued his siege of Harpers Ferry. The first real fighting of the Maryland Campaign was about to begin.
Battle of South Mountain
At nine o’clock in the morning on September 14, elements of the Union Ninth Corps, under Virginia-born general Jesse L. Reno, attacked a small Confederate brigade guarding Fox’s Gap on South Mountain. Fighting spread to another crossing just to the north, Turner’s Gap, where the Union First Corps, under Joseph Hooker, joined the battle and drove the Confederates back. Union troops also attacked farther south, at Crampton’s Gap, which was defended by just a handful of Confederates from McLaws’s division, which was otherwise engaged at Harpers Ferry. Early in the afternoon, Hill’s beleaguered defenders were reinforced by Longstreet’s men arriving from Hagerstown, and by sundown, Union troops had taken Fox’s Gap and Crampton’s Gap but could not quite break the line at Turner’s. Shot by a Confederate sharpshooter at dusk, Reno was among the day’s dead.
By eight o’clock that night Lee realized his campaign was in jeopardy. McClellan’s success at South Mountain had cost the Confederates nearly 3,000 casualties, compared with Union losses of slightly more than 2,000, and if Lee now failed to concentrate his scattered forces in time, then he risked losing his entire army. He ordered McLaws—and likely Jackson and Walker, too—to retreat back across the Potomac and arranged for the rest of the army to regroup at Shepherdstown Ford, in Virginia.
Retreat to Sharpsburg
At daybreak on September 15, somewhere on a ridge east of the small Maryland town of Sharpsburg, Lee surveyed the terrain. High bluffs, clumps of trees breaking up the German farmers’ fields, a sunken road, Antietam Creek—it was eminently defendable. When a messenger arrived with the welcome news that Jackson expected the surrender of Harpers Ferry that morning, Lee decided to call off his retreat and instead gamble on reassembling his army here. He positioned his meager forces to block the pursuit by McClellan’s larger army and then settled in to wait for Jackson.
At Harpers Ferry, Union forces under the command of Colonel Dixon S. Miles ran up a white flag at about eight thirty that morning. After Miles was mortally wounded by a stray shell, Union general Julius White officially surrendered about 12,500 men, their rifles, seventy-three artillery pieces, and other supplies. After a quick breakfast, Jackson began the march to Sharpsburg, with the first of his men arriving at dawn on September 16. Lee quickly placed them on the Confederate left flank, along the Hagerstown Pike. His right flank was securely anchored on Antietam Creek, and the Confederates controlled the southern two bridges of the three that crossed it.
McClellan, looking for an advantage, ordered Hooker’s First Corps to cross at the northernmost bridge and prepare to attack the Confederate left flank first thing in the morning. On the west side of Antietam Creek, near a bit of forest now known as the East Woods, Hooker’s men quickly encountered Confederates under John Bell Hood. A lively firefight flared at dusk and soon settled into sporadic skirmishing that lasted throughout the night.
Battle of Antietam
A light rain fell that night, and the skies remained overcast until about five thirty on the morning of September 17. That’s when Confederate artillery, situated on the high ground northwest of Sharpsburg, opened fire, inaugurating what would become the bloodiest twelve hours in American history.
Lee had spread all of his army—except for A. P. Hill‘s division, which was still marching from Harpers Ferry—along the Hagerstown Pike and across two and a half miles of Maryland countryside. In the north, Confederates held a ridge on the Nicodemus farm, across a cornfield belonging to David R. Miller, and anchored on a plateau near the white-brick Dunker Church and across the pike from the West Woods. D. H. Hill’s men commanded the center of the line, positioned on a farm lane that ran east to west and sank below ground level.
Hooker launched his attack from the Joseph Poffenberger farm and aimed his 9,500 men for the high ground near the church. He initially drove Alexander R. Lawton’s 3,500 Confederates from the Miller cornfield back into the West Woods, but furious counterattacks led by John R. Jones and then John Bell Hood beat Hooker back. After it was repulsed by advancing troops under Union general George G. Meade, one of Hood’s regiments, the 1st Texas Infantry, left more than 82 percent of its men on the field.
By eight thirty in the morning, when McClellan dispatched two divisions of Edwin V. Sumner’s Second Corps to bolster Hooker, thousands of men already lay dead or dying amid broken stalks of corn and the battered remnants of trees. Union general Joseph K. F. Mansfield had been mortally wounded an hour earlier, while Hooker suffered a gunshot wound to the foot. The Confederates hardly fared better. Jackson’s division—named for Stonewall Jackson and containing the famed Stonewall Brigade—had been reduced to only a few hundred men and, with its highest-ranking officers all fallen, was now commanded by a lieutenant colonel. For now, 11,700 Confederates had bent but not broken before 16,500 Union attackers, but Lee had run out of nearby reinforcements. He rushed two divisions in support of Jackson’s men: John Walker’s, at the extreme right of the Confederate line, and McLaws’s, still tired after its night-march from Harpers Ferry.
Beating his Confederate counterparts to the fight, Sumner stopped his men briefly in the East Woods while he reconnoitered the nearly deserted West Woods and the area around Dunker Church. Given another twenty minutes, he hoped to clear the woods of Confederates, establish his artillery on the high ground near the church, and drive the Army of Northern Virginia from the field. Toward that end, Sumner ordered John Sedgwick’s division forward, but at the very moment the Union men entered the West Woods, Lee’s reinforcements arrived. Confederates under the commands of McLaws, Walker, and Jubal A. Early came rushing through the trees and inflicted nearly 2,500 casualties on Sedgwick’s division, with Sedgwick himself—a portly old bachelor from Connecticut—managing to get shot three times. Eventually, the left side of the Confederate line stabilized in what was left of the West Woods.
Following Sumner’s orders from McClellan, Union general William H. French’s 4,500-man division marched to the south, where it encountered D. H. Hill’s 2,500 men holding their position along the Sunken Road. Constituted only a couple of days before the battle, French’s division attacked at about nine thirty and was bolstered by the arrival of Israel B. Richardson’s division. After three hours of savage fighting, what came to be known as Bloody Lane finally fell. At that point, Union general William B. Franklin urged McClellan to give him permission to press the attack, but Sumner—sobered, perhaps, by the sheer number of men killed that day—argued against it, and by the time McClellan personally intervened on Sumner’s behalf, Lee had time to regroup his men and establish a line along the Hagerstown Pike. Although losses for both sides totaled 5,500 out of more than 17,000 men engaged, neither army had been able to fully dislodge the other.
At the same time that Sedgwick and French emerged from the East Woods, Union general Ambrose E. Burnside was to attack the Confederates on their far right, over the southernmost bridge. The idea was to prevent Lee from borrowing troops from his right to reinforce his left, and after a short delay, the attack got started between nine and ten in the morning. Burnside made several small runs at the 500 Confederates on the west bank of the Antietam, but the bridge—an arched, stone walkway—was too narrow to mount an effective charge. Finally, Burnside sent troops downstream, where they found a place to ford the creek and then came upon the Confederates from behind. At the same time, a small storming party made one last rush on what came to be known as Burnside’s Bridge. One Virginia soldier described the fighting as “volumes of musketry and noise of the artillery … mingled in one vast roar that shook the earth.” By one o’clock the crossing was in Union hands.
A two-hour lull ensued while Burnside’s full Ninth Corps (technically under the command of Jacob D. Cox) crossed the bridge and aligned itself for an attack. Only the arrival of A. P. Hill’s division—the last to arrive from Harpers Ferry, and the last of Lee’s reinforcements—saved the day for the Confederates. His men struck Burnside’s men on the left flank and in the rear, halting the Union advance before darkness finally put an end to the fighting. In the preceding twelve hours, nearly 95,000 men had struggled in the fields around Sharpsburg, with about a quarter of those, or approximately 22,700, ending up killed, wounded, or missing. No single-day battle has ever seen as many American casualties before or since September 17, 1862.
That evening both commanders assessed their options. Lee stubbornly refused to retreat, bringing up ammunition and stragglers to prepare to defend his new position. At first, McClellan ordered an attack, but shortages of artillery ammunition and reinforcements, plus a recurrence of a fever he had been battling since the spring, persuaded him to postpone it. On the evening of September 18, Lee reluctantly ordered his men back across the Potomac River at Shepherdstown Ford, while still making plans to move north again on September 20.
After a difficult night-crossing of the river, Lee moved toward Charlestown, leaving a rearguard to prevent Union troops from following. That evening, elements of Union general Fitz-John Porter’s Fifth Corps swept aside the small Confederate force and captured a few pieces of artillery. Once again A. P. Hill’s men saved the day, returning to the ford on the morning of September 20 and driving the Union troops from Virginia.
Lee’s most optimistic hopes for the campaign were dashed. He had not achieved Confederate independence, had not fed his army on the riches of Maryland and Pennsylvania, and far from damaging Union morale, had only boosted it. Still, at a cost of 14,000 casualties, he had fought gallantly. McClellan, meanwhile, had lost nearly twice as many. And after reassembling an army thoroughly demoralized after Second Manassas, marching it seventy miles, and driving Lee from two battlefields, he was content to rest his men rather than continue the pursuit. His was a strategic victory that included the capture of 39 enemy flags, 13 cannon, 15,000 small arms, and 6,000 prisoners. More importantly, it presented Lincoln a huge political opportunity.
After two months of waiting, Lincoln used the victory at Antietam to issue the Emancipation Proclamation on September 22. (It became effective January 1, 1863.) The document offered seceded states the right to return to the Union and keep their slaves, but if they did not, their slaves were declared “forever free.” Slavery itself was not outlawed, owners were not compensated, and newly freed slaves were not made citizens. In addition, the proclamation could not free slaves in non-seceded states, but it did make enslaved African Americans in the Confederate states an economic and political object of the war while satisfying political pressure from Radical Republicans to more forcefully address the slavery question. In the process, the Lincoln administration shifted its reason for fighting from restoring the union to ending slavery. While Confederates were predictably outraged and some Union soldiers grumbled, the shift helped the president diplomatically. England and France had long abolished slavery, and Lincoln correctly judged that they would not now intervene on behalf of a slave state.
Victory at Antietam did nothing to abate a long-simmering tension between Lincoln and McClellan. For political reasons, the president was happy to capitalize on the Army of the Potomac’s success, but he still refused to accord much credit to its leader, whom he viewed as a potential political rival. Even in 1862, it was well established that successful generals became presidents, and the Republicans were not anxious to jeopardize their political control by lionizing McClellan, who was a Democrat.
Lincoln became impatient when McClellan refused to send his exhausted and poorly supplied army after Lee. On October 2, the president visited his general near Sharpsburg and ordered him to march overland to Richmond, a strategy the general, and Winfield Scott before him, had long opposed. When McClellan’s rate of advance did not meet Lincoln’s expectations, he was removed from command on November 5. Not coincidentally, this came one day after the midterm elections, when McClellan’s popularity could no longer hurt the administration.