The unit served as part of the Pennsylvania Reserves for the majority of its service with the Union Army.

On July 12 a scouting party under Kane of sixty men were surrounded by cavalry at New Creek Village, but fought them off, killing eight Confederates and wounding sixteen.

On October 20, it marched to Dranesville, where Colonel Kane was wounded in the mouth while repulsing the Confederates.

At the retreat to Harrison's Landing, Stone and his men constructed a bridge over a stream, possibly saving the Union army.

The regiment was rearmed with Model 1859 Sharps breechloader rifles prior to setting off on the Maryland Campaign.

At Bull Run, Kane was promoted to brigadier general for covering Pope's retreat.

The Pennsylvania Reserves division was severely depleted from months of campaigning and in early 1863, they were sent back to Washington D.C. to rest and refit.

Niles was wounded and Taylor was killed in fighting at the edge of The Wheatfield, leaving Major Hartshorn in command.