Gettysburg campaign
The Gettysburg campaign was a military invasion of Pennsylvania by the main Confederate army under General Robert E. Lee in summer 1863. It was the first time during the war the Confederate Army attempted a full-scale invasion of a free state. The Union won a decisive victory at Gettysburg, July 1–3, with heavy casualties on both sides. Lee managed to escape back to Virginia with most of his army. It was a turning point in the American Civil War, with Lee increasingly pushed back toward Richmond until his surrender in April 1865. The Union Army of the Potomac was commanded by Maj. Gen. Joseph Hooker and then by Maj. Gen. George Meade.
After his victory in the Battle of Chancellorsville, Lee's Army of Northern Virginia moved north for a massive raid designed to obtain desperately needed supplies, to undermine civilian morale in the North, and to encourage anti-war elements. Lee's army slipped away from Federal contact at Fredericksburg, Virginia, on June 3, 1863. The largest predominantly cavalry battle of the war was fought at [|Brandy Station] on June 9. The Confederates crossed the Blue Ridge Mountains and moved north through the Shenandoah Valley, capturing the Union garrison at [|Winchester], in the Second Battle of Winchester, June 13–15. Crossing the Potomac River, Lee's Second Corps advanced through Maryland and Pennsylvania, reaching the Susquehanna River and threatening the state capital of Harrisburg. However, the Army of the Potomac was in pursuit and had reached Frederick, Maryland, before Lee realized his opponent had crossed the Potomac. Lee moved swiftly to concentrate his army around the crossroads town of Gettysburg.
The Battle of Gettysburg was the deadliest of the war. Starting as a chance meeting engagement on July 1, the Confederates were initially successful in driving Union cavalry and two infantry corps from their defensive positions, through the town, and onto Cemetery Hill. On July 2, with most of both armies now present, Lee launched fierce assaults on both flanks of the Union defensive line, which were repulsed with heavy losses on both sides. On July 3, Lee focused his attention on the Union center. The defeat of his massive infantry assault, Pickett's Charge, caused Lee to order a retreat that began the evening of July 4.
The Confederate retreat to Virginia was plagued by bad weather, difficult roads, and numerous skirmishes with Union cavalry. However, Meade's army did not maneuver aggressively enough to prevent Lee from crossing the Potomac to safety on the night of July 13–14.
Background
Lee's plans
Shortly after Lee's Army of Northern Virginia defeated Hooker's Army of the Potomac during the Chancellorsville Campaign, Lee decided upon a second invasion of the North. Such a move would upset Union plans for the summer campaigning season, give Lee the ability to maneuver his army away from its defensive positions behind the Rappahannock River, and allow the Confederates to live off the bounty of the rich northern farms while giving war-ravaged Virginia a much needed break. Lee's army could also threaten Philadelphia, Baltimore, and Washington, and encourage the growing peace movement in the North.Lee had numerous misunderstandings that shaped his strategy. Lee misread Northern opinion by his reliance on anti-war Copperhead newspapers for northern public opinion. Reading them, he assumed the Yankees must be just as war weary as southerners, and did not appreciate the determination of the Lincoln Administration. Lee did know he was seriously short of supplies for his own army, so he planned the campaign primarily as a full-scale raid that would seize supplies. He wrote:
Lee was overconfident of the morale and equipment of his "invincible" veterans as a result of their performance at Chancellorsville; he fantasized about a definitive war-winning triumph:
The Confederate government had a different strategy. It wanted Lee to reduce Union pressure threatening their garrison at Vicksburg, Mississippi, but he rejected its suggestions to send troops to provide direct aid, arguing for the value of a concentrated blow in the Northeast.
In essence, Lee's strategy was identical to the one he employed in the Maryland campaign of 1862. Furthermore, after Chancellorsville he had supreme confidence in the men of his army, assuming they could handle any challenge he gave them.
Opposing forces
Confederate forces
Lee's movement started on the first of June and within a short time was well on its way through Maryland, with Union forces moving north along parallel lines. Lee's cavalry, under General Jeb Stuart, had the primary mission of gathering intelligence on where the enemy position was, but Stuart failed and instead raided some supply trains. He did not rejoin Lee until the battle was underway. Stuart had taken all Lee's best cavalry, leaving the main army with two third-rate, ill-equipped, poorly led brigades that could not handle the reconnaissance challenge in hostile country.Stuart had taken the bulk of the cavalry on a counter-clockwise sweep near the coast behind the Union army and was out of contact with Lee for a week, depriving Lee of knowledge of the federal army. Trying to find Lee, he solved his intelligence problem by reading a Philadelphia newspaper that accurately reported Lee's location. The news was a day old, however, and Stuart, slowed down by a wagon train of booty, did not arrive at Gettysburg until July 2. The Confederates were often aided by uncensored newspaper reports of the movements of Union forces. Hooker tried to censor the newspapers, but reporters and editors evaded his restrictions and the South often had accurate reports of Union strength.
Lee's armies threatened Harrisburg, Washington, Baltimore and even Philadelphia. Local militia units hurriedly formed to oppose Lee, but they were inconsequential in the face of a large, battle-hardened attack force. When Lee finally got news of the approaching Federal army, he ordered his scattered forces to concentrate at Gettysburg, a crossroads junction in heavily wooded areas. Over three days, July 1–3, both armies arrived piecemeal; the Confederate forces from the north and northwest, while Union forces from the south and east. By July 1, Meade was to the south of Lee, cutting off his retreat and forcing him to fight.
Union forces
, commanding the Army of the Potomac, wanted to attack Richmond, but Lincoln vetoed that idea because - in his view - Hooker's goal should have been fighting and defeating the Confederacy's most important army in the field, Lee's Army of Northern Virginia. When Hooker demanded control of the garrison at Harper's Ferry or he would resign, Lincoln accepted and replaced Hooker with George Meade on June 28, just three days before the battle started. The new commander brooked no delay in chasing the rebels north.Meade's advance was sluggish but was further advanced than Lee knew. Lee underestimated his new foe, expecting him to be easy to anticipate and slow to respond, much like Hooker. Meade wanted to defend further south, but when battle was joined at Gettysburg he hastened all corps there.
Taking advantage of interior lines, Meade was close behind Lee, and had cut off the line of retreat back to Virginia. Lee had to fight, but first he had to rush to reassemble his scattered forces at the crossroads town of Gettysburg before Meade defeated them piecemeal. Lee had 60,000 infantry and 10,200 cavalry. This time it was Lee's turn to be fooled; he gullibly accepted misinformation that suggested Meade had twice as many soldiers, when in fact he had 86,000.
Though the main Confederate army was marching through Pennsylvania, Lincoln was unable to give Meade more firepower. The vast majority of the 700,000 Federal soldiers were either tied down occupying Confederate territory, with Grant besieging Vicksburg, with Nathaniel P. Banks besieging Port Hudson, or with William S. Rosecrans maneuvering Braxton Bragg out of Middle Tennessee. Urgently the President called for 100,000 civilian militiamen to turn out for the emergency; being unorganized, untrained, unequipped and poorly led, they were more trouble than they were worth. When the battle began they broke and ran away.
Campaign timeline
The battles of the Gettysburg Campaign were fought in the following sequence; they are described in the context of logical, sometimes overlapping divisions of the campaign.| Action | Dates | Section of campaign |
| Battle of Brandy Station | June 9, 1863 | Brandy Station |
| Second Battle of Winchester | June 13–15 | Winchester |
| Battle of Aldie | June 17 | Hooker's pursuit |
| Battle of Middleburg | June 17–19 | Hooker's pursuit |
| Battle of Upperville | June 21 | Hooker's pursuit |
| Battle of Fairfax Court House | June 27 | Stuart's ride |
| Skirmish of Sporting Hill | June 30 | Invasion of Pennsylvania |
| Battle of Hanover | June 30 | Stuart's ride |
| Battle of Gettysburg | July 1–3 | Gettysburg |
| Battle of Carlisle | July 1 | Stuart's ride |
| Battle of Hunterstown | July 2 | Stuart's ride |
| Battle of Fairfield | July 3 | Lee's retreat |
| Battle of Monterey Pass | July 4–5 | Lee's retreat |
| Battle of Williamsport | July 6–16 | Lee's retreat |
| Battle of Boonsboro | July 8 | Lee's retreat |
| Battle of Funkstown | July 10 | Lee's retreat |
| Battle of Manassas Gap | July 23 | Lee's retreat |
Lee's advance to Gettysburg
On June 3, 1863, Lee's army began to slip away northwesterly from Fredericksburg, leaving A.P. Hill's Corps in fortifications above Fredericksburg to cover the departure of the army, protect Richmond from any Union incursion across the Rappahannock, and pursue the enemy if Hill thought it advantageous. By the following morning, Hooker's chief of staff, General Daniel Butterfield, had received various reports that at least a portion of the Confederate Army was moving. The next day, June 5, Hooker canceled all leave and army furloughs and instructed that all troops be prepared to march if necessary. In the meantime, Longstreet's and Ewell's corps were camped in and around Culpeper. With more Union reports intimating that Lee had moved a large portion of his army, Hooker ordered Sedgwick to conduct a reconnaissance in force across the Rappahannock River.A small skirmish began shortly after 5:00 p.m. as Vermont and New Jersey troops, supported by a heavy Federal artillery bombardment, paddled across the river and overran Confederate positions on the southern bank. As a precaution, Lee temporarily halted Ewell's Corps, but when he saw that Hooker would not press the Fredericksburg line to bring on a battle, he ordered Ewell to continue. The same day as Federal troops crossed the river, General Buford wrote that he had received credible information that "all of the available cavalry of the Confederacy" was in Culpeper County. On June 7, George H. Sharpe, head of the Bureau of Military Information, erroneously reported to Hooker that, while J. E. B. Stuart was preparing a large cavalry raid, Lee's infantry would be withdrawing to Richmond. Hooker decided to preemptively attack the Confederate cavalry force in Culpeper and ordered Cavalry Corps commander Alfred Pleasonton to command the assault.
Lee rejoined the leading elements of his army in Culpeper on June 7 and ordered Albert G. Jenkins' cavalry to advance northward through the Shenandoah Valley. He also wrote to John D. Imboden and ordered him to attract Union forces in Hampshire County and to disrupt their communications and logistics as well as acquire cattle for use by the Confederate Army. To support these movements, Lee wrote to General Samuel Jones and asked him to spare any troops that he could. The following day, he wrote to James Seddon, Confederate Secretary of War, and attempted to persuade him to send troops currently in North Carolina to reinforce either his army or Confederate forces in the west. On June 9, Lee ordered Stuart to cross the Rappahannock and raid Union forward positions, screening the Confederate Army from observation or interference as it moved north. Anticipating this imminent offensive action, Stuart ordered his troopers into bivouac around Brandy Station.