On August 28, 1861, Andrew J. Fulton of Stewartstown mustered 63 southern York County men at Camp Scott, York, Pennsylvania, to form the beginnings of Company C, 87th Pennsylvania Regiment. The company reached its full complement of 100 men a month later. Captain Fulton commanded the company until September 1862 when he accepted the colonelcy of the 166th Pennsylvania Regiment. Captain Murray S. Cross then assumed command.

On September 29, 1861, Company C and four other companies traveled by rail to Cockeysville, Maryland, to help guard the many vital bridges on the Northern Central Railroad between the Maryland border and Baltimore. The regiment spent an uneventful winter stationed over a 30 mile stretch of the track. On June 22, 1862, the eager boys of the 87th boarded a train and headed west only to find themselves saddled with more railroad guard duty, this time the supply depot at New Creek, Virginia (now Keyser, West Virginia). They spent two hot summer months performing inconsequential picket duty until beginning four months of grueling mountain marches in a fruitless search for Rebel guerrillas. On December 24, the exhausted regiment, now part of General Robert H. Milroy's 8th Corps, was assigned a permanent camp at Winchester, Virginia.

Combat had eluded the 87th Pennsylvania but it arrived shockingly on June 13, 1863. Confederate General Richard Ewell's corps, on its way to destiny at Gettysburg, swamped Milroy's badly outnumbered garrison at Winchester. The 87th suffered one-third casualties, primarily captured, sending every man for himself. Those who escaped reformed into two units, one at Harpers Ferry, West Virginia and the other at Bloody Run, Pennsylvania. Not until late September did they reunite as members of the 3rd Corps, Army of the Potomac. In November they took part in the abortive Mine Run campaign and spent the winter camped at Brandy Station, Virginia.

The following March the regiment was transferred to General John Sedgewick's 6th Corps and took part in the bloody battles of the 1864 Overland Campaign. In July they were detached to General Lew Wallace only to suffer defeat at the Battle of Monocacy. Later, detached duty sent them to the Shenandoah Valley to engage in the more successful battles of Fishers Hill and Opequon under General Phillip Sheridan.

In October 1864 their three-year enlistment had expired. Those who had not re-enlisted returned to a grateful York to a celebratory feast given by the town at the Army Hospital at Penn Commons. The 200 remaining members of the regiment played an important role at the Battle of Cedar Creek. There, Corporal Daniel Reigle of Company F earned the regiment's only Medal of Honor. The regiment returned to Petersburg, Virginia, and were part of the action that broke the Confederate lines there. Recruits and conscripts filled out the muster rolls, and the now full-sized regiment took part in the smashing victory at Sailor's Creek in April 1865. They were encamped just a few miles from Appomattox Court House when General Robert E. Lee surrendered to General Ulysses S. Grant.

On June 14th, 1863, the 87th Pennsylvania Regiment, as part of the 8th Army Corps under the command of General R. H. Milroy, occupied the fortifications just outside of Winchester, Virginia. There they were assaulted by superior numbers of Confederate forces under General Jubal Early and a fierce battle ensued. Outnumbered and low on rations and ammunition, Milroy decided to withdraw and under cover of darkness, the men evacuated the fortifications. Less than five miles from Winchester, the Federal forces encountered the enemy en masse near the railroad tracks at Carter's Woods (Stephenson's Depot).

During the fierce fighting that followed, Corporal Johnston Skelley of Company F, fell mortally wounded. Less than three weeks later on the morning of July 3rd, as Skelley lay dying in Winchester, his fiance, Jennie Wade was struck in the back by a Confederate sniper's bullet, killing her instantly. Dying with a picture of Skelly in her pocket, she became the only civilian killed at the battle of Gettysburg. On July 12th, Skelley succumbed to his wounds. Neither ever learned of the other's fate.