The 1st Pennsylvania Reserves were assembled at Camp Wayne near West Chester, Pennsylvania on June 9, 1861 and mustered into the service on July 26, 1861 at Camp Carroll near Baltimore, Maryland under the command of Colonel Richard Biddle Roberts. The regiment was attached to the following throughout the war:
Dix's Command, the regional organization of troops led by John Adams Dix to September 1861
1st Brigade, 3rd Division, I Corps, Army of the Potomac, to February 1863
1st Brigade, Pennsylvania Reserves Division, XXII Corps, to June 1863
1st Brigade, 3rd Division, V Corps, Army of the Potomac, to June 1864.
The 1st Pennsylvania Reserves mustered out June 10, 1864.
Detailed service
Moved to Harrisburg, Pa., July 20; then reported to General Dix at Baltimore, Md., July 22, 1861. Moved to Annapolis, Md., July 27. Duty at Annapolis, Md., July 27 to August 30, 1861. Moved to Washington, D.C., then to Tennallytown, Md., August 30–31. Marched to Langley October 10, and duty at Camp Pierpont until March 1862. Reconnaissance to Dranesville December 6, 1861. Action at Dranesville December 20. Advance on Manassas, Va., March 10–15. McDowell's advance on Fredericksburg, Va., April 9–19. Duty at Fredericksburg until May 31. Ordered to the Virginia Peninsula June. Seven Days before Richmond June 25-July 1. Battles of Mechanicsville June 26, Gaines Mill June 27, Charles City Cross Roads and Glendale June 30, and Malvern Hill July 1. At Harrison's Landing until August 16. Movement to join Pope August 16–26. Battle of GrovetonAugust 29. Second Battle of Bull Run August 30. Maryland Campaign September 6–24. Battle of South Mountain September 14. Battle of Antietam September 16–17. Duty in Maryland until October 30. Movement to Falmouth October 30-November 19. Battle of Fredericksburg, December 12–15. "Mud March" January 20–24, 1863. Ordered to Washington, D.C., and duty in the defenses there until June 25. Rejoined the Army of the Potomac. Battle of Gettysburg, July 1–3. Pursuit of Lee July 5–24. Williamsport July 13. Bristoe Campaign October 9–22. Advance to line of the Rappahannock November 7–8. Rappahannock Station November 7. Mine Run Campaign November 26-December 2. Mine Run November 26–30. Rapidan Campaign May and June 1864. Battle of the Wilderness May 5–7; Laurel Hill May 8; Spotsylvania May 8–12; Spotsylvania Court House May 12–21. Assault on the Salient May 12. Harris Farm May 19. North Anna River May 23–26. Jericho Ford May 25. Line of the Pamunkey May 26–28. Totopotomoy May 28–31. Left front June 1.
Casualties
The regiment lost a total of 174 men during service; 6 officers and 102 enlisted men killed or mortally wounded, 2 officers and 64 enlisted men died of disease.
Commanders
Colonel Richard Biddle Roberts - resigned November 1, 1862