Lee’s first venture into the North had ended in failure. Unable to win at Antietam, he had failed to crush Northerners’ will to fight and he had failed to convince Great Britain to extend diplomatic recognition to the Confederacy.  Therefore in June 1863, he decided to try again. He would march north to Pennsylvania.  The Army of the Potomac would have to pursue.  And when it did, Lee would choose the best ground to fight a major battle—one designed to terrify the Northern public and impress British statesmen.

The first stage of Lee’s campaign went according to plan.  He marched swiftly up the Shenandoah Valley with the Union army under Joe Hooker paralleling his movements 30 miles to the east.  Hooker had proposed attacking Richmond while Lee moved North—but his plan was rejected in Washington.  After getting whipped at Chancellorsville, despite having the much larger army, he had little credibility or support.  In fact, by the end of June he had been replaced by General George Meade.

While the Union army may have lacked effective leadership, Lee suffered from poor intelligence.  The usually reliable J.E.B. Stuart had decided to ride all the way around the Union army in order to gather troop information.  Lee was accustomed to the daring antics of his over-achieving Major General, but Stuart’s decision was costly.  Stuart’s ride took longer either anticipated; for three critical days Lee heard nothing from Stuart and was forced to march into enemy territory without really knowing where the Union army was positioned.

Lee was therefore stunned to hear on 28 June that the Union army was closer than he thought. His army was dispersed along a 40-mile arc—and he had only the most general information about his enemy’s position and strength.  This was not the way he planned it. From the beginning, his goal had been to pick the ground on which to fight.  Now short on information, and hurried in his efforts to collect his army, events were moving outside his control.

In fact, the decision to fight at Gettysburg was largely made by a small group of Confederate soldiers who went into the town looking for shoes and saddles.  They bumped into a division of Northern cavalry and had to fight their way back to their lines.

On the next day, 1 July 1863, a sort of preliminary contest ensued as neither army had arrived in full strength.  The fighting began with two Confederate infantry divisions attacking the Union cavalry under John Buford.  Through the morning, the fighting occurred to the west of the town; by afternoon, the arrival of more troops had extend the action to the town’s north. For the most part, the Southerners got the best of the engagements—Union casualties were higher and, in general, they were forced to fall back. At one point, Union soldiers ran frantically through the streets of the town with the rebels in hot pursuit.  But also, for the most part, these Union forces fell back to high, easily defended ground. By the end of the day they commanded a two-mile horseshoe that ran from Culp’s Hill along Cemetery Ridge to the Roundtops.

Lee had not chosen this ground and the Union defensive position was stronger.  Trusted advisors, most importantly James Longstreet, counseled him to withdraw to better ground.  But Lee was impressed by his troops’ performance on the first day.  And so he decided to take his stand here and attack the Union lines the next day.

On 2 July Lee began his attack by hitting the North’s left flank at the Peach Orchard, Little Roundtop, and Devil’s Den. Only the fortuitous re-positioning of a small Maine regiment prevented the rebel forces from sweeping around the Union flank and crashing the backside of the North’s lines.   While Longstreet worked the Union left, Richard Anderson led a division against the center of the Union lines dug in along Cemetery Ridge.  These Confederate troops also almost broke through; they reached the cemetery gates before being driven back.  The day’s fighting ended with yet another Confederate attack, this time against the North’s right flank on Culp’s Hill. It too was repelled by Union troops.

The following day, Lee decided to pull Union troops from the center with an attack on the right flank atop Culp’s Hill, and then hit the center with the bulk of his army.  But a Union attack on the forces gathering for Lee’s flanking action forced these troops into combat earlier than Lee wanted.  By the time Longstreet was ready to lead the assault on the Union center, the attack on the right had already been turned back, and the Union center was reinforced.

Despite this failure, Lee stuck with his plan.  He launched a ferocious artillery barrage aimed at softening the Union center; then he ordered Major General George Pickett to lead 15,000 men across almost a mile of open fields while Union artillery and rifle fire tore them to shreds.  One unit managed to reach the Union lines.  But the attack was really doomed from the start.

Lee knew it was over.  The next day he led his beaten troops back toward Virginia.  He had lost almost 28,000 men—roughly a third of his army.  Perhaps more important, his own confidence was shaken.  He wrote Confederate president Jefferson Davis offering to resign his position—Davis would hear nothing of it.  But Lee, his army, and the Confederate cause would never be the same.

Union General George Meade briefly celebrated his victory, the largest Union victory to date and his first since replacing Hooker.  But his moment quickly passed.  Sensing the end, Lincoln ordered Meade to pursue the shattered Confederate forces.   Meade did but very cautiously. Lee managed to escape into Virginia.  Meade was soon taking orders from Ulysses S. Grant.