American Civil War: Invading the North

Back: The Shenandoah Valley

Maryland and Antietam
Pennsylvania and Gettysburg

Robert E. Lee firmly believed that for the Confederacy to survive he needed to win a major victory on Northern soil. He was to get two chances to put this theory to the test, and each case he was to loose his battle.

Maryland and Antietam

In each case, Lee was able to launch his invasion because of victory won on southern soil. 1862 had seen the North launch a massive invasion of Virginia. After the failure of McClellan’s Peninsular Campaign, Lee was able to shift his troops back north, where they helped win the Second Battle of Bull Run or Manassas (29-30 August).

In the aftermath of Bull Run, Lee wanted to launch an invasion of Maryland. If successful, this would threaten Washington, possibly bring Maryland into the Confederacy, and perhaps convince Northern public opinion that the south could not be conquered.

Lee was confident that his army was now capable of beating anyone, but especially the defeated and, he hoped, demoralised northerners. This was his first mistake. The Union soldiers withdrawn from the Peninsular and their colleagues beaten at Second Bull Run may have been downhearted, but not demoralised, and they maintained their confidence in General McClellan, now restored to command of the army to defend Maryland.

Not all of Lee’s army accompanied him north into Maryland. A significant number of his men were actually moderately pro-union, fighting for the south because they were opposed to any compulsion being used against the seceded states, or had enlisted to defend their home states against northern aggression and did not approve of southern aggression. All in all, Lee took 50,000 men into Maryland on 4 September, crossing the Potomac about thirty miles west of Washington.

On 7 September Lee’s army stopped at Frederick, north of its crossing point. There Lee hoped to recruit secessionist Marylanders, but the secessionist areas of the state were further east and south. The first part of Lee’s plan to fail was his hope for reinforcements from Maryland.

The same day saw McClellan lead an 85,000 Union army out of the Washington defences to face Lee. Another 72,000 men were left behind to defend Washington. This was a serious mistake, not because McClellan’s army was too small, but because he had convinced himself that Lee had 100,000 men, and so he was outnumbered!

Lee’s original plan had been to march north through Maryland into Pennsylvania, but he now allowed his entire campaign to be derailed by the small Federal garrison at Harpers Ferry, to his west on the Potomac. On 10 September Lee’s army left Frederick, and headed west. Lee now took a massive gamble, splitting his army into five segments. Three were to concentrate against Harper’s Ferry, while two guarded the routes east and north. Lee was confident that he could capture Harpers Ferry and reunite the army before McClellan got anywhere near, or possibly even before he realised that Lee had split his forces.

This was improbable to say the least. McClellan was receiving a great deal of accurate intelligence about Lee’s movements now he was in Maryland, but on 13 September he received a stroke of luck that should have allowed him to role up Lee’s entire army. A copy of Lee’s Special Order 191, detailing his plan for the attack on Harpers Ferry, was found by two Union solders. Worse, the copy was written in handwriting that was recognised as belonging to Lee’s assistant adjutant-general. The order was genuine, and McClellan accepted it as such.

Even with this information, McClellan still proved incapable of moving quickly. On 14 September he managed to force his way through the mountain passes north of Harpers Ferry, but then halted again. Harpers Ferry did not fall to the Confederates until the following day, 15 September. On that same day, Lee decided to move his part of the army, some 15,000 men, south to Sharpsburg, with Antietam Creek running south to north just to his east. The first Federal units reached the east bank of the creek at noon on the same day.

This was McClellan’s great chance. The bulk of his army was no more than half a days march away. On 15 September he could have attacked Lee’s 15,000-20,000 men with most of his 80,000. The following day part of the Harpers Ferry force reached Lee, but even at the end of the day he only had 25,000 men. Still McClellan did not attack.

Finally, on 17 September McClellan attacked. The resulting Battle of Antietam or Sharpsburg saw a series of determined but uncoordinated Union attacks that came close to breaking Lee’s line on several occasions. On each occasion, McClellan failed to support the attack, and convinced that he was still outnumbered never used his reserves. Antietam saw the highest casualty figures of any single days fighting in the entire war. Lee lost 2,700 dead, 9,024 wounded and 2,000 missing out of a total force of 40,000. Union losses were 2,108 killed, 9,549 wound and 753 missing out, similar total numbers out of a much larger army.

McClellan was given yet another chance on 18 September. Lee remained in his lines all day, with his forces down to at most 30,000 men. McClellan had nearly that many fresh soldiers who had taken no part in the fighting on the previous day, but was still convinced that Lee had massive reserves, and did not attack. Finally, during the evening of 18 September Lee withdrew across the Potomac back into Virginia.

Antietam was McClellan’s last great chance to defeat Lee. On 7 November he was finally replaced as commander of the Army of the Potomac. He persisted in claiming Antietam as a military masterpiece. Although it was far from that, it did have long reaching effects. For some time Lincoln had been waiting for a victory before issuing the Emancipation Proclamation. Antietem was enough of a victory. The Proclamation helped change the nature of the war, giving the Union cause a great moral advantage. Antietam also discouraged any thoughts the British government might have had about recognising the Confederacy. Lee’s gamble had failed.

Pennsylvania and Gettysburg

The following year gave Lee a better opportunity to invade the north. After defeat at Fredericksburg (13 December 1862) and Chancellorsville (2-5 May 1863), the Union Army of the Potomac was in no shape to launch any more attacks in 1863. McClellan was gone, and no commander had yet to maintain the trust of the army. Lee could launch his second invasion of the north in the summer of 1863 with some hope of winning a significant victory on Northern soil. For once, Lee was not hugely outnumbered. His own army was as large as it had ever been, while thousands of Union soldiers who had enrolled for nine months in the summer of 1862 left the army when their period of enlistment ended.

This time his target was Pennsylvania, further north and with no secessionist minority. Here his army could legitimately strip the countryside bare without any scruples about upsetting potential Confederate supporters. The invasion of Pennsylvania certainly produced an impressive quantity of booty. Nearly 50,000 cattle and sheep moved south into Virginia as Lee’s army moved north.

This time, Lee’s army did move north. On 3 June the Second Corps of the Army of Northern Virginia left its camps at Fredericksburg, and headed north west to the Shenandoah Valley. On 14-15 June it pushed aside the Union garrison of Winchester (Second battle of Winchester), and on 15 June crossed the Potomac into Maryland. On 14 June the Army of Potomac left its own camps opposite Fredericksburg and began to march north in pursuit of the Confederate army.

For the next two weeks the armies moved north. Lee’s army behaved with deliberate restrain, in the hope of encouraging the pro-peace Democrats in the north, although still managed to extort large amounts of valuable Northern money. The Union army, still under Joe Hooker, was slowly closing on them, although Hooker was still somewhat stunned by his Chancellorsville defeat, becoming increasing uncertain as he approached Lee.

One of the acknowledged weaknesses in Lee’s leadership was that he was unwilling to give clear and unambiguous orders to his subordinates. To do so would be an insult to them as fellow gentlemen. This approach had worked reasonably well with Thomas Jackson, who had normally performed as required, but with other men it simply allowed them to do what they wanted. In the case of Jeb Stuart that meant heading off on another raid around the rear of the enemy army. On 25 June he left with three brigades on a raid that lasted a week, and left Lee without effective scouts.

It took until 28 June for Lee to learn that Hooker and the Army of the Potomac were just behind him in Maryland. Hearing the news, Lee began to pull the three corps of his army back together, ready to fight his climatic battle.

On the same day Hooker was finally replaced. After an argument with General-in-Chief Halleck, Hooker had offered his resignation, and on 28 June it was accepted. He was replaced by Major-General George Meade. Meade was a relative unknown, who had commanded a division at Fredericksburg that had nearly pierced the Confederate line, and had risen to Corps command since. Only three days after being appointed to command the entire army, Meade was to find himself involved in the most famous battle of the war, commanding a recently beaten army against Lee’s confident veterans.

That battle developed around the small community of Gettysburg. Lee had decided to concentrate his army in the general vicinity of the town, an important road junction. As they were going to be in the area anyway, A.P. Hill ordered one of his divisions into Gettysburg to seize a supply of shoes said to be in the town.

On the morning of 1 July, this division found Gettysburg defended by two brigades of Union cavalry. Those brigades had arrived on the previous day. Their commander had noticed that the hills around Gettysburg would make a strong defensive position, and had sent word to the nearby infantry corps commanded by John Reynolds. Reynolds set his men on the road to Gettysburg.

On 1 July these cavalry brigades were able to hold off Hill’s infantry for two hours, until the first brigade of Reynold’s corps arrived on the scene. They were soon joined by the Union 11th Corps and the lead divisions of Ewell’s Confederate Corps. The first of the army commanders to arrive on the scene was Lee. He arrived to find 24,000 of his men facing 19,000 Union solders to the north and west of Gettysburg. Lee ordered a general assault, four divisions strong. The Union forces were swept from their positions, and forced to withdraw through Gettysburg to their reserve position on Cemetery Hill, half a mile south of the town.

Lee’s style of command now led to one of the great controversies of the war. Although his army had had the best of the fighting so far, the Union army still held a strong position south of the town. If Lee was to gain his army-crushing victory, then he would need to deal with that position before the rest of the Union army arrived. Accordingly, he gave orders to Ewell to attack, but left the final judgement on whether to attack that day to Ewell. Ewell, who had replaced Stonewall Jackson, chose not to attack. This was probably the right choice. His men had been fighting all day, while there was already at least one fresh Union division on Cemetery Hill, and more men were arrived all the time. By the time Ewell could have organised an attack, the Union position of Cemetery Hill would almost certainly been strong enough to repel his attack with heavy losses. His decision has become yet another of the Confederacy’s ‘if only’ moments. If Jackson had not been killed, he would have attacked Cemetery Hill on 1 July. If Jackson had attacked, he would have swept the Union defenders off the hill. If the Union defenders of Cemetery Hill had been swept off the hill, the Confederacy would have won the war. Jackson’s track record at the Seven Days Battles does not fill one with confidence about this series of ifs.

Overnight the bulk of both armies arrived around Gettysburg. Meade’s line stretched south from Cemetery Hill along Cemetery Ridge to Little Round Top, and east to Culp’s Hill. However, on his southern flank, General Sickles had moved his Corps west, to higher ground along a road that ran south west out of Gettysburg, in an area known as the Peach Orchard. This position presented a stronger front than Cemetery Ridge, which was not of any great height at this point, but left Sickles’s Corps exposed on both flanks. 

Lee planned a two pronged attack for 2 July. On his right, Longstreet was to attack Cemetery Ridge in force. On his left, Ewell was to act as if he was about to attack, and then turn his demonstration into a real attack if Meade weakened the Union right to deal with Longstreet. If all went well, both flanks would crumble, allowing Lee to surround the strong Union centre on Cemetery Hill.

Unfortunately, Lee was let down by Longstreet. Despite orders to attack as early in the day as possible, Longstreet’s attack did not go in until 4 in the afternoon.  Worse, Sickle’s decision to move forward to the Peach Orchard meant that after several hours of intense fighting, in which the Union forces were pushed slowly back and back, all Longstreet achieved was to push the Union line back to Cemetery Ridge, where he had expected to find them in the first place. A great chance to seize Little Round Top, at the southern end of the Union line was also missed. Finally, towards dusk, the Union Sixth Corps reached the battlefield, and was immediately placed into the front line. Longstreet’s attack had failed.

On the Confederate left, Ewell’s attack inevitably went in late, as he was waiting for Meade to react to Longstreet’s attack. When Ewell did go in, he was able to seize lightly defended Union positions on Culp Hill, but it was too late in the day for him to achieve any more. The next morning a Federal counterattack was to retake these positions.

Lee decided to try one more attack on 3 July. This time he would attack the centre of the Union line, on the northern part of Cemetery Ridge. Lee was able to form a force 13,500 strong to launch this attack, supported by 160 guns. However, the artillery bombardment was ineffective. The Union soldiers were safe behind stone field walls and their own breastworks, besides which most of the Confederate guns were firing too high. Eventually the Union guns ceased firing, simply to conserve ammunition and await the coming attack. This was taken as a signal that the Confederate bombardment was having the required effect, and the attack was ordered in.

Picket’s Charge has become known as the High Water Mark of the Rebellion. His 13,500 men marched into devastating Union artillery fire, and then those that did get close to the Union line were exposed to the concentrated musket fire of the undamaged Union infantry. One can not help but think of the slaughter on the Western Front, just over fifty years later. No more than a few hundred of Pickett’s men reached the Union positions on Cemetery Hill. The Confederates suffered around 7,000 casualties during Pickett’s Charge, and achieved nothing. Lee had demonstrated a similar stubbornness at Malvern Hill in the previous year. He had entered Pennsylvania to fight a war winning battle, and he was not willing to give up after two days.

After three he was left with no choice. On 4 July his army was too battered to launch another assault. Meade’s army was in slightly better shape, although was not in a fit state to launch its own counterattack. After staying in place at Gettysburg until about one in the afternoon of 4 July, Lee began a skilful retreat back to Virginia. The great gamble had failed. As Lee was pulling back from Gettysburg, the garrison of Vicksburg on the Mississippi was marching out to surrender. East and west the Union was victorious.

Lee was later to say of Gettysburg that ‘the battle resulted in the infliction of as great an amount of injury as was received and in frustrating the Federal campaign for the season’. The second claim was credible (although the defeat at Chancellorsville and the disappearance of a large part of the Union army when their enlistments ended also played a part), but the first was not. Confederate casualties were over 28,000, with 3,903 killed and 18,735 wounded. The Union army lost 23,000 men (3,155 killed and 14,529 wounded). These were casualties that the Confederacy could not afford.

Lee’s reason for attacked the north was that he felt that victories in Virginia could not win the war. An examination of the casualty figures would suggest that this was not the case. At Chancellorsville, earlier in the year, the Union had suffered 17,000 casualties and the Confederacy 13,000. In the following year, Grant’s army was to suffer much the higher casualties – 17,600 compared to 7750 at the Battle of the Wilderness and 17,700 against 12,000 at Spotsylvania. These heavy Union casualties came close to costing Lincoln the 1864 Presidential election. How much more damage could Lee have done if he had still had the veterans lost at Gettysburg?

Lee’s aim at Gettysburg was the destruction of the Union army. The entire campaign was launched in the belief that it was still possible to win a battle that would destroy your opponent’s army, either directly through inflicting casualties, or preferably by out-manoeuvring them and forcing the army to either surrender or disintegrate. The ambition of commanders on both sides was to win an Austerlitz style of victory (At that battle Napoleon had destroyed the Austrian and Russian armies on a single day – 2 December 1805). Lee was not alone in looking for this sort of victory. When Grant launched his 1864 campaign he still had some hopes of winning a great manoeuvre battle, but Grant had already come to realise that this might not be possible, and was prepared to alter his plans if needed. By 1863 it should have been increasingly clear that the Union Army of the Potomac was capable of recovering from the most severe defeats – Second Bull Run had been followed by Antietam. Would not a Confederate victory at Gettysburg have been followed by another Union revival, and another battle?

Next: Clearing the Mississippi

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A Great Civil WarA Great Civil War, Russel F. Wiegley, Indiana University Press, 2004, 648 pages. This is a superb account of the civil war years. Weigley has produced a book that combines a good understanding of the military aspects of the war with a clear grasp of the wider issues at stake. [see more]
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How to cite this article: Rickard, J (1 May 2006), American Civil War: Invading the North ,

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