Gettysburg Campaign

June 3–July 23, 1863

Fought during the summer of 1863, the Gettysburg Campaign culminated with the Union Army of the Potomac's victory over the Confederate Army of Northern Virginia at the Battle of Gettysburg on July 3.

Robert E Lee, 1864, Portrait

Robert E. Lee’s 1863 campaign into the North saw the Army of Northern Virginia suffer a major defeat at Gettysburg.


Prelude to the Gettysburg Campaign

In early May 1863, Confederate General Robert E. Lee and his Army of Northern Virginia soundly defeated Major General Joseph Hooker and his Army of the Potomac at the Battle of Chancellorsville. Despite the Rebel victory, Lee’s army needed food, horses, and equipment after the battle. With northern Virginia ravaged by two years of combat, Lee took the war to the North. Lee planned to disengage from Union forces near Fredericksburg, move the Army of Northern Virginia northwest across the Blue Ridge Mountains, and then push northeast through the Shenandoah Valley into Maryland and Pennsylvania. Lee began gathering his army near Culpeper, Virginia, and troop movements began on June 3, 1863. To mask his intentions and screen the assembly of his invasion force, Lee stationed his cavalry, commanded by Major General J. E. B. Stuart, at Brandy Station, a few miles northeast of Culpeper.

Battle of Brandy Station (June 9, 1863)

Union officials mistakenly interpreted Lee’s cavalry deployment as evidence of an impending attack on Hooker’s supply lines or, perhaps, an assault on the nation’s capital. Stung by the defeat at Chancellorsville, Hooker went on the offensive and ordered Major General Alfred Pleasonton to lead his cavalry corps, augmented by 3,000 infantrymen, in a two-pronged attack to “disperse and destroy” the enemy cavalry. At 4:30 a.m. on June 9, 1863, roughly 5,500 Federal troopers crossed the Rappahannock River, surprising Stuart’s pickets at Beverly’s Ford. At the same time, 2,800 more Federal soldiers crossed the Rappahannock at Kelly’s Ford, about four miles downstream.

At approximately 11 a.m., Union forces surprised Stuart a second time as he approached Brandy Station from the south. A series of charges and countercharges followed until late afternoon when Pleasonton ordered a withdrawal as Rebel reinforcements began to arrive.

Despite being surprised twice on the same day, Stuart drove his attackers from the field. The Rebels suffered fewer casualties than the Federals, technically making the engagement a Confederate victory. Still, the Battle of Brandy Station, the largest cavalry battle of the Civil War, served as a morale booster for the battered Army of the Potomac by showing that the Union cavalry was emerging as a worthy opponent for their formerly, far-superior Confederate counterpart.

Second Battle of Winchester (June 13 and June 15, 1863)

After the Battle of Brandy Station, Lee’s army continued their trek northwest toward Winchester in the Shenandoah Valley where roughly 6,900 Union troops were garrisoned under the command of Brigadier General Robert Milroy. As Richard Ewell and his Corps approached Winchester, Milroy began concentrating his forces, despite instructions from Washington to evacuate and fall back to Harpers Ferry.

On June 14, Ewell established artillery positions on the high ground west of town and he began bombarding the Federal defenders. The Rebels then overran Milroy’s small fort and batteries guarding the west side of town. By 9 p.m., Milroy called a council of war with his subordinates and determined to evacuate his troops. Aware of Miroy’s predicament, Ewell sent Major General Edward “Allegheny” Johnson’s Division on an overnight, flanking march to cut off the Federal withdrawal.

Early the next morning, Milroy unsuccessfully tried three times to break through the Rebel lines blocking his retreat. When reinforcements arrived, Johnson launched a counterattack, and the Yankees began surrendering. Escorted by a few hundred cavalrymen, Milroy escaped and eluded pursuing Confederate troops. Ewell’s victory at the Second Battle of Winchester cleared the upper Shenandoah Valley of Union resistance, paving the way for Lee’s invasion of Maryland and Pennsylvania.


Battle of Aldie (June 17, 1863)

As Lee continued to move north on the west side of the Blue Ridge Mountains, he ordered Stuart’s Cavalry Division to move in the same direction through the Loudoun Valley on the east side of the mountains, screening the Confederate invasion force. Lee instructed Stuart to prevent Federal reconnaissance forces from advancing through gaps in the mountains to gather information about the Army of Northern Virginia’s movements.

Frustrated by the lack of intelligence about Lee’s operation, on June 16, 1863, Hooker ordered Pleasonton, “to give him information of where the enemy is, his force, and his movements.” On June 17, Pleasonton ordered Major General David Gregg to take his division to seize and occupy the village of Aldie, Virginia, where two strategic roads leading through the mountains converged.

A Federal assault at about 2:30 p.m. quickly pushed the outnumbered Rebel defenders out of Aldie until reinforcements arrived. The Confederates then pushed the Yankees back into the village, taking control of the high ground west of town. Following a short lull during the Battle of Aldie, the rest of the day featured fierce, but indecisive, cavalry engagements around the two turnpikes. At about 8 p.m., Stuart withdrew, because Lee needed his troopers at another engagement at nearby Middleburg. When night fell, Pleasonton held the junction of the two turnpikes, but he had gained no significant information about Lee’s progress on the west side of the mountains.

Battle of Middleburg (June 11–June 19, 1863)

Concurrent with the attack on Aldie on June 17, Pleasonton also ordered an assault on the hamlet of Middleburg about five miles to the west of Aldie. Union troopers easily took control of the lightly guarded village and nearly captured Stuart who was having a leisurely lunch when the Blue Coats arrived. As evening approached, Confederate troopers returned and surrounded the Yankees, who lost over 200 soldiers as they tried to escape the Rebel trap the next morning.


On June 19, Federal cavalry recaptured Middleburg. About one mile west of town, Confederate troopers established a defensive line on Mount Defiance. Repeated Union attacks on the Grey Coats throughout the day proved fruitless. As the day progressed, more Federal troopers arrived on the scene. Facing the possibility of being overwhelmed, the Rebels withdrew to the west along another ridge near the town of Upperville. Although the Yankees regained control of the town after the Battle of Middleburg, Stuart’s cavalry forces still blocked their path through the Blue Ridge Mountains.

Battle of Upperville (June 21, 1863)

Pleasonton rested his troops during a daylong downpour on June 20, before renewing his efforts to penetrate Stuart’s cavalry screen. At Pleasonton’s request, Hooker deployed infantry units to support the Union cavalry. Meanwhile, Stuart was gathering his cavalry near Upperville.

On Sunday, June 21, a Union cavalry brigade, supported by infantry, assaulted Stuart’s troopers east of Upperville. The outnumbered Confederate force withstood the initial Federal surge but gradually withdrew westward toward town. Following pitched fighting on two fronts Stuart fell back, taking up a stronger defensive position at the Ashby Gap through the Blue Ridge Mountains. Pleasonton chose not to press the issue and returned to Aldie, ending the Battle of Upperville. Once again, Stuart’s strategy of giving up ground to buy himself time to maneuver deprived Pleasonton of vital information about Lee’s movements, which he was desperately seeking.

Battle of Hanover (June 30, 1863)

After the battle of Upperville, Lee approved Stuart’s plan to leave two brigades guarding the passes through the Blue Ridge Mountains, and to ride east with his remaining three brigades. Stuart intended to maneuver himself around the rear of the Union army and then ride north to join Ewell’s Corps in Southern Pennsylvania. Stuart’s objectives were to gather intelligence about the Army of the Potomac’s movements and commandeer supplies if possible. Departing on June 25, Stuart plundered a Federal supply depot near Rockville, Maryland on June 28, capturing a train of 150 wagons. Because he sensed no urgency, Stuart slowed his return to the main army by taking his bounty with him, rather than destroy it.


On June 30, 1863, Stuart’s cavalry surprised the rearguard of the Union cavalry division under the command of Brigadier General H. Judson Kilpatrick as it was leaving the village of Hanover, Pennsylvania, sending the Yankees scurrying into town. Upon hearing the sounds of gunfire, Kilpatrick’s column reversed course and mounted a spirited counterattack, driving the Grey Coats back out of the village. The ensuing action quickly developed into a full-scale cavalry engagement in and around Hanover. Skirmishing continued as both commanders positioned their big guns, setting the stage for a two-hour artillery duel during the afternoon. As the day progressed, Stuart became convinced that Kilpatrick had gained the advantage and withdrew toward York, Pennsylvania, with his captured wagon train.

Although casualties were light on both sides, the Battle of Hanover was a significant engagement because it delayed Stuart’s arrival at the Battle of Gettysburg until mid-afternoon of the second day of the pivotal conflict on July 2. Stuart’s late arrival deprived Lee of vital information about Union troop deployments before the battle, and his absence also limited the effectiveness of the Army of Northern Virginia during the first two days of the engagement.

Battle of Gettysburg (July 1–3, 1863)

As Stuart was completing his ride around the Union army, Lee had little access to information about the status of his enemy, which was quickly changing. On June 27, Hooker impulsively offered to resign his position as commander of the Army of the Potomac after a dispute with Union general-in-chief Henry W. Halleck. The next day, President Abraham Lincoln accepted Hooker’s resignation and assigned the post to Major General George G. Meade. Upon assuming his new command, Meade quickly began moving north from Frederick, Maryland in search of Lee’s army in Pennsylvania. When Lee finally learned of Meade’s aggressive pursuit, he ordered his scattered army to gather at Cashtown, about eight miles west of the village of Gettysburg, Pennsylvania.


June 30

On June 30, a brigade of Confederate soldiers from the corps under the command of A. P. Hill approached Gettysburg from the northwest in search of supplies. Upon their arrival, they observed Union cavalry commanded by Brigadier General John Buford entering the town from the south. Avoiding an engagement, the Rebels returned to Cashtown to report what they had seen. Suspecting that his soldiers had seen state militia, rather than Federal troopers, Hill sent two brigades into Gettysburg the next morning to investigate.

July 1

Recognizing the strategic importance of the high ground near Gettysburg, Buford ordered his troopers to dismount and attempt to hold the town until reinforcements arrived from the 1st Corps of Major General John F. Reynolds. Once the surprised Hill determined that he was facing Federal cavalry, he called up more soldiers and launched an assault on the Union defenders, despite Lee’s orders to avoid a general engagement until he could reunite the Army of Northern Virginia.


Notwithstanding Lee’s wishes, the opening day of the Battle of Gettysburg grew in size and intensity as it progressed. Lee reached the field around noon, still hoping to avoid a major battle at a site with which he was unfamiliar. Near then, however, Reynolds’ men began arriving, repulsing the Confederate advance. Although Rebels soon killed Reynolds, Major General Oliver O. Howard was on hand with his 11th Corps and took command of the combined Federal forces. During the afternoon, Ewell’s Corps arrived from the north, reinforcing the Rebel onslaught. The combined Confederate force sent Howard’s men scurrying out of town, leaving behind 3,500 captives. The Yankees took up a defensive position south of town on Cemetery Hill. Still wishing to avoid a major battle, Lee decided not to continue the attack.

Overnight, reinforcements poured into Gettysburg. By morning, each army was nearly at full strength. Meade had deployed six of his seven divisions in a fishhook-shaped defensive line on the high ground south of town. Lee had amassed eight of his nine divisions and was preparing to resume the offensive, despite his reservations from the day before. What began as an accidental encounter on July 1 evolved into a full-scale showdown over the next two days.


July 2

Lee’s battle plan on July 2 called for General James Longstreet to take his corps, augmented by part of A. P. Hill’s Corps, and attack Meade’s left flank, which Major General Daniel Sickles and his 3rd Corps anchored on a small hill known as Little Roundtop. Lee’s strategy also called for the rest of Hill’s Corps to prevent Meade from reinforcing Sickles by threatening the Union center. Finally, Lee ordered Ewell to feel out the Union right and make an all-out attack if practicable.

Longstreet objected to the plan, arguing that the reinforced Federals held better ground. Instead, Longstreet proposed marching around the Union army, placing the Confederates between Meade and the nation’s capital, thus forcing a fight upon the ground of their choosing. Lee held fast, and the offensive began at 3:30 p.m., several hours late. The delay gave Meade extra time to deploy troops and improve his defenses.

Besides being tardy, the Rebels did not coordinate the assault well. Hill’s advance against the Union center did not prevent Meade from reinforcing his left. Faced with blistering Confederate onslaughts at Little Round Top, Devil’s Den, the Wheatfield, the Peach Orchard, and Cemetery Hill, the Federal defenders held their ground. Later that evening, Ewell belatedly launched unsuccessful attacks at Cemetery Hill and Culp’s Hill. At the end of the second day, the Rebels had bloodied the Army of the Potomac, but the Yankees maintained their control of the high ground at Gettysburg.

July 3

On July 3, fighting continued on both flanks, but Lee focused his attention on the center of Meade’s line. At about 3 p.m., following two hours of heavy artillery bombardment, a force of about 12,500 Grey Coats, led by Major General George Pickett, Brigadier General J. Johnston Pettigrew, and Major General Isaac R. Trimble, began a frontal assault on Cemetery Ridge. During the attack, the Confederates briefly breached the Union line, but the Federals recovered and repulsed Pickett’s Charge. The Rebels suffered nearly 50% casualties during the ill-fated assault.


After three days of fighting, the combined armies suffered between 45,000 and 51,000 casualties, including nearly 8,000 dead, making Gettysburg the bloodiest battle of the Civil War.

Battle of Williamsport (July 6–16, 1863)

Following the Union victory at the Battle of Gettysburg, Lee halted his second invasion of the North. At roughly 5:p.m. on July 4, Brigadier General John D. Imboden led a long train of Confederate wounded and supplies toward the Potomac River crossings at Williamsport and Falling Waters, about 50 miles to the southwest. Lee ordered the rest of the army to follow using a different route the next day.

The withdrawal soon came to a halt when heavy rains swelled the Potomac River, preventing the Confederate army from crossing back into Virginia. Forced to wait until the river receded, Lee established a long, semi-circular defensive line near Williamsport, anchored on his left by the Conococheague Creek and on his right by the Potomac River at Falling Waters.

On July 5, Meade learned that Lee had left Gettysburg. Despite prodding from his superiors in Washington to pursue the Confederate general aggressively and destroy his army, Meade settled for dispatching his cavalry to harass the retreating Grey Coats. Meade had reason to be cautious. The previous three days of battle had exhausted and battered his army. Unsure of the extent of the damages inflicted upon the Confederates, Meade also needed time to gather information to determine if Lee intended to withdraw to Virginia or to make another stand north of the Potomac. Finally, orders to guard against a possible Rebel assault on Washington and Baltimore hampered Meade’s flexibility.

After reconnaissance missions determined that Lee was retreating, Meade divided his army into three columns and ordered a more vigorous but still cautious pursuit. Throughout the pursuit, Meade was careful to keep his main force between Lee and the nation’s capital.


Over the next week, the two armies sparred in several cavalry clashes around the Williamsport area. On July 6, 1863, Brigadier General Judson Kilpatrick’s Union cavalry division tried unsuccessfully for six hours to dislodge Stuart’s cavalry from Hagerstown. Stuart’s victory maintained control of important roads leading to Williamsport. On the same day, Union Brigadier General John Buford launched an ill-fated cavalry assault against Imboden at Williamsport. The Confederate general summoned enough artillery and defenders to hold off a three-hour Federal onslaught, saving the Rebel stores and wounded from being captured.

By July 12, Meade had his army (now numbering as many as 95,000 soldiers) positioned to assault the Rebel defenses. By that time, however, the river had nearly receded enough to accommodate the Confederate retreat. During the night of July 13, most of Lee’s army crossed the Potomac. On June 14, Meade ordered a general advance by four divisions, only to find that most of the Confederates had returned to Virginia soil. Meade captured several hundred Rebels during rearguard engagements on July 14 and July 16.

The Battle of Williamsport was arguably more important for what did not happen, as opposed to what did. Much to the chagrin of his superiors, including President Lincoln, Meade’s measured pursuit of the trapped Confederate army enabled Lee to hang on long enough to escape across the Potomac after the rain-swollen waters receded. Coupled with the Union victory at the Vicksburg, led by Ulysses S. Grant, Meade possibly lost an opportunity to end the Civil War in 1863, two years before its actual conclusion.

Battle of Boonsboro (July 8, 1863)

Following the failed assault on Stuart’s cavalry at Hagerstown on July 6, the Federal cavalry fell back to Boonsboro, along the National Road roughly twelve miles southeast of Hagerstown and Williamsport. As Lee waited for the flooded Potomac River to recede, he ordered Stuart’s cavalry to advance upon the Union cavalry at Boonsboro to prevent the Yankees from gaining control of the South Mountain passes, thus hindering Meade’s access to the Confederate army stranded at Williamsport.


On July 8, 1863, Stuart advanced toward Boonsboro with four cavalry brigades. The action began when Brigadier General William E. “Grumble” Jones’ brigade encountered Federal pickets near Beaver Creek about 4.5 miles north of Boonsboro. As the Confederates pushed forward, they engaged Union cavalry forces at about 11 a.m. on rain-soaked, muddy fields outside of town. Sloppy conditions forced the troopers on both sides to dismount and fight like infantrymen. The Battle of Boonsboro, which was the largest cavalry conflict in Maryland during the Gettysburg Campaign, raged throughout the afternoon. At roughly 7 p.m. Federal infantry began arriving on the scene, forcing Stuart to withdraw north to Funkstown. Although the results of the battle were inconclusive, Stuart successfully delayed Meade’s movement toward Williamsport, buying more time for Lee’s retreat to Virginia.

Battle of Manassas Gap (July 23, 1863)

After returning to Virginia, Lee’s army traveled south, up the Shenandoah Valley, toward Front Royal. Still hoping to trap the Confederates, Meade ordered Major General William French and his 3rd Corps to cross the Blue Ridge Mountains and cut off the Rebels at Front Royal. On July 23, French assaulted Confederate troops entrenched on Wapping Heights overlooking a pass through the mountains known as Manassas Gap. Spirited fighting by the Yankees throughout the day forced the Rebel defenders to concede ground until soldiers from Major General Robert E. Rodes’s Division reinforced them. When the fighting ended at dusk, the Federals had taken possession of the pass. French called a halt to the assault at dusk, and during the night the Confederates withdrew. The next day, French continued to Front Royal, only to discover that he was too late to cut off Lee’s army as it marched south up the valley to safety.

The results of the Battle of Manassas Gap were inconclusive. Although French forced the Confederate defenders off of Wapping Heights and taking possession of Manassas Gap, he failed in his attempt to cut off Lee’s retreating army. Following Lee’s escape, Meade abandoned any further pursuit of the Confederate army, thus ending the Gettysburg Campaign.


Aftermath of the Gettysburg Campaign

The Gettysburg Campaign created mixed results that favored the Union. Lee relieved the pressure on war-ravaged Virginia during the summer of 1863. He also captured vast amounts of much-needed food and other supplies. Still, his invasion did not demoralize the North or erode support for the Lincoln administration. Moreover, the Federal victory at the Battle of Gettysburg put the Army of Northern Virginia in a defensive posture for the rest of the Civil War.


Citation Information

The following information is provided for citations.

  • Article Title Gettysburg Campaign
  • Date June 3–July 23, 1863
  • Author
  • Keywords Gettysburg Campaign
  • Website Name American History Central
  • Access Date March 27, 2023
  • Publisher R.Squared Communications, LLC
  • Original Published Date
  • Date of Last Update March 2, 2023

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