Battle of Gettysburg Begins in American Civil War

Context

Following his victory at Chancellorsville in May 1863, Confederate General Robert E. Lee reorganized the Army of Northern Virginia into three infantry corps under generals A. P. Hill, James Longstreet, and Richard S. Ewell, with cavalry under J. E. B. Stuart. Lee then launched a second invasion of the North, hoping to draw Union armies away from Virginia, threaten major cities, and possibly secure European diplomatic recognition for the Confederacy.

Union General Joseph Hooker, who had been defeated at Chancellorsville, was replaced by George G. Meade as commander of the Army of the Potomac on June 28. Meade’s forces moved north to shadow Lee’s army, which had crossed into Pennsylvania. Stuart’s cavalry, sent on a wide raid, lost contact with Lee, depriving the Confederate commander of timely intelligence about Union movements.

By late June, elements of both armies were converging on the crossroads town of Gettysburg, Pennsylvania, initially drawn there by reports of supplies and the need to concentrate forces east of South Mountain.

What Happened

Early on July 1, a Confederate division under Henry Heth, part of A. P. Hill’s corps, advanced from the west toward Gettysburg in search of shoes and other supplies. Union cavalry under Brigadier General John Buford delayed the advance west of town, buying time for infantry reinforcements. Major General John F. Reynolds, commanding the Union I Corps, arrived with his troops and was killed early in the fighting near the Lutheran Seminary.

As the morning progressed, additional Confederate units from Hill’s and Ewell’s corps arrived from the west and north. They engaged Union I and XI Corps troops in intense fighting around McPherson Ridge and Oak Ridge. By afternoon the numerically superior Confederate forces pushed the Union defenders back through the streets of Gettysburg itself.

By evening the surviving Union troops had fallen back to the high ground south of town, occupying defensive positions on Cemetery Hill and Culp’s Hill. Confederate commanders considered but ultimately declined an immediate assault on these positions as daylight faded.

Aftermath

The Union army retained control of the commanding heights south of Gettysburg, allowing Meade to concentrate his remaining forces and prepare stronger defenses for the following days. Lee, arriving on the field, elected to continue offensive operations rather than disengage, committing his army to two more days of fighting.

Both sides suffered thousands of casualties on the first day alone, with Union losses including the death of a senior corps commander and the temporary disorganization of two corps.

Legacy

The three-day battle ended Lee’s northern invasion and is widely viewed as the turning point of the American Civil War, after which the Confederacy remained on the strategic defensive in the East. The battlefield later became the site of a national cemetery dedicated in November 1863, where President Abraham Lincoln delivered the Gettysburg Address.

Historians continue to study the engagement for its tactical lessons, the role of leadership decisions on July 1, and its demonstration of the war’s immense human cost, with total casualties exceeding 50,000.