Everyone on both sides of the battlefield, including McClellan, fully expected the battle to restart on September 18th. Most of the men figured that the Yankees would drive at the Rebels once more in an attempt to crush Lee's army on the banks of the Potomac. McClellan thought otherwise. He believed the battle would continue but he was determined that he wouldn't be the one to continue it. He had set up a defensive position in preparation for the Confederate counterattack he still expected. McClellan was completely certain that Lee greatly outnumbered him.
McClellan had the virtually untouched Fifth and Sixth corps, Pleasanton's cavalry, and Couch's division. The rest of his army was bloodied, but no worse so than Lee's. McClellan had 30,000 men from the previous day's battle, 26,300 fresh troops (most of them veterans), and 6,000 raw recruits in the division of Brig. Gen. Andrew A. Humphreys of Porter's Fifth Corps. This gave McClellan more than 62,000 men. Lee opposed him with about 28,300 infantry and artillery-men, and 4,500 cavalry, almost all of whom had been engaged the previous day. McClellan made no move to attack Lee. On the night of the 18th/19th, Lee withdrew his army across the Potomac.
Covering Lee's retreat were 44 guns from Lee's reserve artillery, under the command of Brig. Gen. William Pendleton, and two small brigades of infantry. The guns were set up on the bluffs on the Virginia side of the Potomac River, overlooking Boteler's Ford which was about a mile from Shepherdstown, Virginia (in a section of the state that is now West Virginia). Union cavalry arrived on the Maryland side of the river soon after dawn. They probed the Confederate position for about two hours until they were relieved by men of Porter's Fifth Corps. An artillery duel began between the two sides, with some Union shells landing in Shepherdstown. Union sharpshooters began picking off Confederate gunners. Just before dark about 500 Federals crossed the river under cover of an artillery barrage. They forced the Confederate infantry back, which had been spread out to defend the guns. The Confederates retreated with most of their guns.
In the darkness and confusion, Pendleton reported to Lee that the entire artillery reserve had been captured and Federals were in Virginia. In actuality Porter's men had captured only five guns and had crossed back into Maryland for the night. Lee and Stonewall Jackson reacted by sending the divisions of A.P. Hill and Jubal Early back to the ford and drive the Federals back across the river. Around 7 a.m. on September 20, Porter sent three brigades across the river. As they marched towards Shepherdstown advance skirmishers encountered the lead elements of Hill's division. Porter ordered the men back to the Maryland side of the river. One regiment, the 118th Pennsylvania, refused until the regiment's commander, Col. Charles M. Prevost, received orders directly from his immediate superior. This was the first engagement for this newly formed regiment. Hill's men slammed into them as they deployed on top of the bluff. The Pennsylvania men found that many of their Enfield rifles were defective. Col. Prevost was wounded. Other officers in the regiment attempted a bayonet charge, but it was wrecked by the Confederates and the regiment broke apart. Many men fell to their deaths trying to escape down the bluffs. Of the 700 men in the regiment, only 431 made it back across the river.
This two-day long engagement became known as the Battle of Shepherdstown, and it marked the end of Lee's Maryland invasion.
As news of the battle at Antietam leaked out it became apparent that McClellan had squandered a chance for a decisive victory. The Army of Northern Virginia was back in Virginia. For Lee, the battle was a temporary set back. He intended to move towards Williamsport, cross back into Maryland and drive his army north. He soon discovered that this was easier said than done. Straggling was a major problem. Many weary or wounded men simply walked away from the army and headed home. An infuriated Lee instructed the cavalry to round up the stragglers, but this proved to be like catching water with a net. He had to finally admit that the army had been as wounded in spirit as it had been in body and that offensive operations were not feasible, for the time being. On September 25 Lee wrote to Confederate President Jefferson Davis, "I would not hesitate to make it even with our diminished numbers, did the army exhibit its former temper and condition; but, as far as I am able to judge, the hazard would be great and a reverse disastrous. I am, therefore, led to pause." The army made camp in the Shenendoah Valley.
Even though the Army of Northern Virginia had escaped its grasp, the Army of the Potomac could still do it grave harm. Instead, it continued to sit in the fields around Sharpsburg. McClellan called for supplies and reinforcements. His troops needed uniforms. His cavalry needed new horses. Union troops camped on the battlefield buried the dead. Days went by with the Federal army showing no intention of pursuing the Confederates.
Antietam wasn't the clear victory that Lincoln desired, but it was still technically a victory. On September 22 Lincoln announced his preliminary Emancipation Proclamation. All slaves in the Southern states not occupied by the Union or part of the Union on January 1, 1863 would be declared free. If Southerners wanted to retain their slaves they had to rejoin the Union before the end of 1862. After that date, any Confederate territory captured by the North would result in the freedom of any slaves in that territory. The proclamation did not free the slaves in northern territory or in southern territory already captured by the Union.
The proclamation was accepted with mixed reaction in the North and condemnation in the South. Northern abolitionists were happy to see the war become one of liberation, but abolitionists were still a small minority. Many in the Union reacted with skepticism and fear. There were worries that large numbers of free slaves would travel north looking for freedom and jobs. Many in the Union armies had fought to preserve the Union and wanted no part in fighting — and potentially dying — for the slaves. The Union, like the rest of the world in 1862, was intensely racist. The Southern reaction was more predictable, with Confederates calling Lincoln's address everything from a terrible evil to the act of a desperate man. It was unlikely that any Confederate state would rejoin the Union under the terms of the proclamation. Lincoln, of course, knew this. While it appeased the radicals in the North, the proclamation was written for a foreign audience.
In Britain and France, the reaction was negative at first. British papers condemned Lincoln. The main worries were that it would lead to a slave revolt, and that a desperate South would fight bitterly, resulting in the war spiraling downward into barbarism. Few took seriously the idea that the South would surrender by the end of 1862. Lincoln didn't expect the Emancipation Proclamation to end the war. Instead, it was a declaration to the South that there would be no return to the status quo. The United States would fundamentally change as a result of the war, either with the Confederacy gaining independence or with the abolition of slavery in a reunited nation. This implied that a Union victory would end slavery while a Confederate win would perpetuate it. The British and French government could not support a slave state because the people of those countries — which were democracies, after all — were vehemently against slavery. Up until then, the anti-North elements tried to show that Lincoln cared nothing for the slaves, that he was only hungry for power. After the proclamation was announced the common people of Europe saw Lincoln in a different light, and there was a sharp rise in sympathy for the Union.
British politicians were quick to see the implications. Lord Palmerston, the British Prime Minister, had planned a cabinet meeting to discuss recognition of the Confederacy. There was talk of bringing Russia in to side with the Confederacy, along with Britain and France. On October 11, the day before Palmerston was to discuss Confederate recognition with his cabinet, he received more news from America about the war and the proclamation. Palmerston postponed the cabinet meeting. The idea of recognizing the Confederacy was never put before the cabinet. As Lincoln himself noted in January, 1862, "I cannot imagine that any European power would dare to recognize and aid the Southern Confederacy if it became claear that the Confderacy stands for slavery and the Union for freedom."
The reaction to the proclamation was largely negative in the Army of the Potomac. The minority abolitionists welcomed it, but many in the army resented it. Chief among these were members of McClellan's staff. Some talked openly about marching on Washington and replacing Lincoln with McClellan. McClellan never encouraged this sentiment, but neither did he do much to quell it. He didn't like the Emancipation Proclamation but he was unsure how he should respond to it. He had his eyes set on the Democratic Party's nomination to run for president in 1864. There were political risks if he came out in favor of it or if he came out against it. In the end he chose to sidestep the issue. Instead, in a general order issued on October 7, he reiterated that the army was an instrument of the people and that it owed it's allegiance to the people — and the president — of the United States. McClellan wanted no part of a coup or mutiny.
Meanwhile, the Army of the Potomac still hadn't budged. The army was still in no shape to fight, according to Little Mac, and the enemy was still too strong. Frustrated with McClellan's failure to move against Lee, Lincoln took a train to western Maryland on October 1 to visit the army unannounced. He met with several officers, including Alpheus Williams, and spent a great deal of time reviewing the troops, touring the battlefield, and visiting field hospitals. At one point Lincoln was on some high ground overlooking the army. He turned to an acquaintance from Illinois, Ozias M. Hatch, who was accompanying him and he asked, "Do you know what this is?" A puzzled Hatch answered, "It is the Army of the Potomac." "So it is called," replied Lincoln, "but that is a mistake; it is only McClellan's bodyguard."
The historical highlight of the visit occurred on October 2, when Lincoln met with McClellan and the two talked in private. No one was present to record the conversation. Both men came away from the meeting feeling positive about it and believed they had made their positions known. On October 4, Lincoln took a train back to Washington. It wasn't long before Lincoln realized that he hadn't made much of an impression on his reluctant general. Lincoln would later say to his secretary, John Hay, "I went up to the field to try to get him to move & came back thinking he would move at once. But when I got home he began to argue why he ought not to move."
On October 6, a telegraph arrived at McClellan's headquarters from Maj. Gen. Henry Halleck, commander-in-chief of Union armies. It read, in part, "The President directs that you cross the Potomac and give battle to the enemy or drive him south. Your army must move now while the roads are good..." McClellan replied that he was "pushing everything as rapidly as possible in order to get ready for an advance". He asked for more supplies and provisions, and asked for repairs to the Harpers Ferry - Winchester rail line.
On the morning of October 10, Jeb Stuart and 1,800 cavalrymen crossed the Potomac a few miles upstream of Williamsport. Their target was the rail line running from Pennsylvania and Hagerstown. They were to collect booty and intelligence. By nightfall they had arrived at Chambersburg, Pennsylvania, 20 miles in McClellan's rear. They tried to destroy the railroad bridge there, but it was iron and resisted their efforts. They did manage to capture 1,200 horses from Pennsylvania farmers, destroy $250,000 worth of government property, and capture Longstreet's ammunition train, which had been taken by Grimes Davis after his breakout from Harper's Ferry. On October 12 Stuart recrossed the Potomac at White's Ford near Leesburg, having completely circled the Army of the Potomac at the cost of one man wounded and two captured. While a relatively minor raid in the total scheme of the war, it served to humiliate McClellan. This was the second time Stuart had ridden completely around his army.
Lincoln dearly wanted rid of McClellan but his hands were tied for political reasons. The 1862 mid-term elections were almost upon Lincoln and he was stuck on the horns of a dilemma. If he removed McClellan yet again, it would look like the administration was incompetent and had no idea how to prosecute the war. McClellan was popular, particularly with War Democrats. Removing him would be disastrous for the Republican Party at a critical election period. On the other hand, while in command of the army McClellan was the administration's instrument for fighting the war. Whatever he did or did not do reflected on the administration. If McClellan continued to do nothing, it too would look bad on Lincoln and the Republicans. Lincoln chose to verbally push McClellan into action. He also gave McClellan one last chance to redeem himself.
The army still hadn't moved by October 13. On that day Lincoln wrote a letter to McClellan. "My Dear Sir: - You remember my speaking to you of what I called your over-cautiousness. Are you not over-cautious when you assume that you cannot do what the enemy is constantly doing? Should you not claim to be at least his equal in prowess, and act upon the claim?" Lincoln continued, "As I understand, you telegraphed General Halleck that you cannot subsist your army at Winchester unless the railroad from Harpers Ferry to that point be put in working order. But the enemy does now subsist his army at Winchester, at a distance nearly twice as great from railroad transportation as you would have to do, without the railroad last named ... I certainly should be pleased to have the advantage of the railroad from Harpers Ferry to Winchester; but it wastes all of the remaining autumn to give it to you, and, in fact, ignores the question of time, which cannot and must not be ignored."
Lincoln then set one final test for McClellan. "... you are now nearer Richmond than the enemy is, by the route that you can take and he must. Why can you not reach there before him, unless you admit that he is more than your equal on the march? His route is the arc of the circle, while yours is the chord ... I would press closely to him, fight him if a favorable opportunity should present, and at least try to beat him to Richmond. I say 'try'; if we never try, we shall never succeed..." Lincoln made it clear that the target was Lee's army, not the Confederate capital. "As we must beat him somewhere, or fail finally, we can do it, if at all, easier near us, than far away." Lincoln explained the advantage the Union army had in reinforcements and supplies, then he wrote, "It is all easy if our troops march as well as the enemy; and it is unmanly to say they can not do it."
The Army of the Potomac was between the Army of Northern Virginia and Washington. The Union army was also closer to Richmond than Lee's army. McClellan could travel on an arc towards Richmond, keeping himself between Lee and Washington. Lee would also have to travel on an arc, but a much longer one. McClellan should have been able get to Richmond before Lee. This was Lincoln's test. If McClellan could get to Richmond first and force an encounter with the Southern army, McClellan would remain as head of the Army of the Potomac. If he could not, he would be replaced.
On October 22 McClellan informed Washington that he would follow Lincoln's recommendation, but he needed more infantry and cavalry. On October 24 the army still hadn't moved. McClellan replied to a telegraph from Halleck asking about the movement of the army. He said he was ready to move against Lee, but that he needed more horses. The horses he had were "absolutely broken down from fatigue and want of flesh". A furious Lincoln replied to McClellan on the 25th. "I have just read your dispatch about sore-tongued and fatigued horses. Will you pardon me for asking what the horses of your army have done since the battle of Antietam that fatigues anything?" In all fairness to McClellan, the army was in the middle of a hoof-in-mouth disease outbreak. Still, this underscored Lincoln's growing impatience with the commander of his largest army. The next day an offended McClellan informed Lincoln that the army was crossing the Potomac. Lincoln replied with something of an apology, claiming that he had intended "no injustice to any". It was clear, though, that Lincoln's patience had all but run out.
It took the Army of the Potomac nine days to cross the river bearing its name. Lee's Army of Northern Virginia had done the same thing in a single evening. As the Union army plodded across the river, Lee moved elements of his own army to counter the Union advance. By November 4, Longstreet's corps had marched 60 miles and had arrived at Culpeper, putting himself across the Union line of advance between the Union army and Richmond. McClellan had failed the test. November 4, 1862 was election day.
On Friday, November 7, Ambrose Burnside received orders from Brig. Gen. Catharinus P. Buckingham personally. Buckingham was the War Department's adjutant general. Fearing a coup d'etat by McClellan, Buckingham was sent to give Burnside and McClellan their orders. If Burnside refused to accept his, Buckingham was to return to Washington without seeing McClellan. The orders instructed Burnside to take command of the army. In spite of Burnside's lackluster performance at Antietam and South Mountain, he had performed well with an independent command in North Carolina earlier that year. He was a friend of McClellan's and well liked by his men. Lincoln felt that it would be less disruptive to the army if Burnside took command. Burnside didn't want the job. He felt he wasn't qualified to command the entire army. Buckingham made it clear, though, that if he didn't take command then the position would pass to Joe Hooker. This was something Burnside could not live with. He reluctantly accepted. Buckingham then went to McClellan and handed him a set of orders that relieved him of command and sent him home to wait for another assignment.
Burnside asked McClellan to stay on for a few days to help with the change over. Though some officers spoke of the very coup the politicians feared, McClellan would have nothing of it. Many in the army were sad at McClellan's departure. Hardened soldiers wept openly at the thought of losing Little Mac. These feelings weren't universal. Men of Burnside's Ninth Corps were less upset about it. They felt that they had been left unsupported by McClellan and were pleased with Burnside's promotion. It was telling that Robert E. Lee wasn't particularly happy to see McClellan depart. He remarked to Longstreet, "I fear they may continue to make these changes till they find some one whom I don't understand."
After a formal ceremony on November 10, 1862 command was officially handed over to Burnside. The next day, the Young Napoleon boarded a train headed for his home in New Jersey. Members of his honor guard broke ranks, uncoupled the train car, and called for McClellan to stay. McClellan came out and calmed them. He asked them to pledge allegiance to Burnside. His car was recoupled, and the train took Little Mac from the Army of the Potomac for good.
The Emancipation Proclamation allowed Lincoln to seize the moral high ground. The European nations, which were once close to recognizing the Confederacy, backed away. The South lost its best chance of gaining recognition. With European intervention far less likely, they were on their own. They would have to win the war militarily against an enemy with greater resources and a much larger population. Even so, the conflict would continue for almost 3 more bloody years with the end result in doubt for much of that period.
The elections of 1862 were a close thing. Seven pro-administration governors lost their jobs, including the governor of New York. This was important because governors were instrumental in raising troops from their state. However, the Republicans were able to maintain control of both the House of Representatives and the Senate. Lee's invasion of Maryland ended at Antietam and Shepherdstown. In the west, Confederate Maj. Gen. Braxton Bragg's Army of the Mississippi was defeated by Maj. Gen. Don Carlos Buell's Army of the Ohio on October 8 at the Battle of Perryville, Kentucky, in a contest that was poorly fought by both sides. If the Lost Order had never been found and if Bragg had not been stopped in Kentucky, there would have been Confederates in Pennsylvania and Ohio on the eve of the election. The Republicans would have almost certainly suffered a defeat at the polls and a "lame duck" Lincoln would have been at the mercy of the Democrats, who were leaning toward an end to the war on terms favorable to the Confederacy.
McClellan returned to his home in Trenton, New Jersey to await new orders that never came. He was ordered before the Committee on the Conduct of the War in 1863 to explain his performance at the battle. He ran for president as the Democratic Party's candidate in 1864, but he was hampered by the party's platform of ending the war. Though at one point it looked like he might win the election, a string of Union successes handed Lincoln the victory with McClellan taking only 3 states. McClellan resigned from the army on election day, and eventually became governor of New Jersey from the late 1870s to the early 1880s. He was stung by criticism of his handling of the battle. After Burnside's death in 1881, he declared that his initial order for Burnside to advance went out an hour before it actually did, in a somewhat successful effort to push the blame on Burnside. Not only was this untrue, it ignored the fact that an aggressive McClellan could have destroyed Lee on September 16, at several points on the 17th, and while the two armies sat before each other on the 18th. McClellan himself died in 1885.
The men of Cpl. Mitchell's regiment, the men who found the order, suffered gravely in the battle. Mitchell's company, Company F, sustained 40% casualties during Twelfth Corps' attack on the Cornfield. Mitchell, Sgt. Bloss, and Pvt. Campbell (his friend, who read the order over his shoulder) were all wounded. The company commander, Capt. Kopp, was killed. No reward, promotion, commendation, or mention in dispatches was made for Mitchell. He was severely wounded in the leg, spent 8 months recuperating, and then was transferred to the ambulance service. After the war his health declined, and he died in 1868 after his disability rendered him bedridden. Col. Colgrave, his regimental commander, first mentioned Mitchell in his account in 1886 for Century magazine, but he said Mitchell was a private instead of a corporal. Bloss tried to take credit for the find, stating that he had told Mitchell to pick up the packet for him to see. This was eventually dispelled, though the erroneous account of Bloss as the finder of the Lost Orders crops up from time-to-time. While Mitchell died in relative obscurity, today we know him as the man who handed McClellan his "victory", a victory that should have been decisive but which McClellan came very close to throwing away.
As to the Lost Order itself, no one is sure how it came to be lying in a clump of clover in that Maryland field. Lee himself (contrary to popular belief that he heard about it on September 14) only learned of the Lost Order sometime in early 1863, after the New York Journal of Commerce published McClellan's January 1, 1863 testimony before Congress. The order was definitely supposed to go to D. H. Hill, but Hill claimed it never arrived. Hill had acted on a copy of the orders given to him by Stonewall Jackson, and written in Jackson's own hand. Since Hill was still under Jackson's command it was entirely proper for Hill to receive his orders directly from him, thus Hill himself didn't find anything amiss.
Chilton claimed that nothing was wrong on his end, so supposedly he received the return receipt. This is impossible because the return slip was the order's envelope. The recipient was supposed to sign the envelope proving that he received it, and the courier was supposed to return the signed envelope to headquarters. Since the envelope was found with the orders and the cigars inside, it stands to reason that Harvey Hill never received the order and — contrary to what Chilton said — Lee's staff never received the return receipt.
After the war Hill vehemently denied receiving the order. In 1867, a Richmond newspaper editor, E. A. Pollard, claimed that Hill tossed the order away, angry at being detached to guard duty. In 1876, the Count of Paris related a story of Hill leaving the order lying carelessly on a table in his headquarters. In 1884, former Confederate General Bradley T. Johnson told of the order falling from Hill's pocket as he rode through Frederick. Since it is only a rumor that Hill's troops had camped in the field where the order was found — he was posted to a location on the Monocacy River several miles away — these accounts are unlikely.
Also unlikely is the charge that a treacherous courier placed the orders so they would be found by the Union. While a courier was discovered to be a Yankee spy and hanged shortly after the Harper's Ferry operation, only an incredibly optimistic agent would drop the orders in a field hoping that they would be found in time to be of use.
The likeliest explanation is that a courier lost the packet in transit and had perhaps covered up the lack of a return receipt. In any event, the Confederates didn't investigate the matter. Even when the information that the order was wrapped around three cigars was made known in the 1880s, no memories were triggered and no recalcitrant courier stepped forward to take the blame. The order remains one of the most unlikely, and mysterious, quirks of fate in military history.