Overview
The 11th Pennsylvania Infantry (Three Years’ Service) was an infantry regiment from Pennsylvania that served in the Union Army during the American Civil War. Organized primarily from recruits in Lycoming, Clinton, Luzerne, Northumberland, Montour, and Westmoreland counties, the regiment was mustered in at Harrisburg between late 1861 and November 27, 1861, for a three-year term of service. The 11th Pennsylvania Infantry was notable for being the first three years’ regiment from the state and participated in many of the major campaigns of the Army of the Potomac.
This unit is distinct from the 11th Pennsylvania Infantry (Three Months’ Service).
Organization & Service
After the expiration of its three months’ service, the 11th Pennsylvania Infantry was reorganized at Harrisburg and mustered in for three years’ service, with mustering completed by November 27, 1861. The regiment initially comprised nine companies, totaling 813 men, with a tenth company assigned but never joining. The regiment spent the winter of 1861–1862 at Annapolis, Maryland, before moving to Washington, D.C., in April 1862. From there, it was posted along the Manassas Gap Railroad near Manassas Junction.
Assigned to the Army of Virginia, the 11th Pennsylvania participated in the battle of Cedar Mountain in August 1862. Shortly thereafter, a detachment for the tenth company joined the regiment, and the unit was engaged in the defense of Thoroughfare Gap. The regiment suffered heavy losses at the Second Battle of Bull Run and was also active at Chantilly, Antietam, and Fredericksburg through the end of 1862.
In January 1863, the regiment took part in the “Mud March” and remained in camp at Fletcher’s Chapel until the Chancellorsville campaign in late April. At Gettysburg, the brigade, including the 11th Pennsylvania, captured approximately 500 prisoners. The regiment continued to serve with the Army of the Potomac through the Mine Run campaign and into 1864. In January 1864, over three-fourths of the men reenlisted, qualifying the regiment as a veteran unit. After a furlough, the regiment returned to service with 590 men and participated in the Wilderness, North Anna River, Bethesda Church, Cold Harbor, Petersburg, and Weldon Railroad operations.
The 11th Pennsylvania Infantry remained with the Army of the Potomac through the final campaigns of early 1865, including the Appomattox Campaign. Following the surrender of Confederate forces at Appomattox Court House, the regiment returned to Harrisburg and was mustered out in early July 1865.
Research This Regiment Further
If you’d like to explore this unit’s history in more depth, regimental histories and Civil War reference works offer valuable detail.
Engagements & Campaigns
- Cedar Mountain
- Thoroughfare Gap
- Second Bull Run
- Chantilly
- Antietam
- Fredericksburg
- “Mud March”
- Chancellorsville
- Gettysburg
- Mine Run Campaign
- The Wilderness
- North Anna River
- Bethesda Church
- Cold Harbor
- Petersburg
- Weldon Railroad
- Appomattox Campaign
Casualties
Specific casualty figures for the 11th Pennsylvania Infantry (Three Years’ Service) are not fully detailed in the available primary sources. The regiment sustained significant losses in several major battles, including heavy casualties at Second Bull Run. At Falling Waters during the earlier three months’ service, the regiment lost 1 man killed and 10 wounded. For the three years’ service, comprehensive totals for killed, wounded, and disease-related deaths are not provided in the cited sources.
Some details are incomplete in surviving primary sources.
Field Officers & Commanders
- Colonel Richard Coulter
- Lieutenant Colonel Thomas S. Martin
- Lieutenant Colonel Henry A. Frink
- Lieutenant Colonel Benjamin F. Haines
- Major Henry A. Frink
- Major John B. Keenan
- Major Benjamin F. Haines
- Major John B. Overmeyer
Regimental Roster
The full roster of officers and enlisted men who served in the 11th Pennsylvania Infantry (Three Years’ Service) is available on a dedicated roster page. This roster provides names, ranks, and additional service details valuable for genealogical and historical research.
To view the complete roster, visit the 11th Pennsylvania Infantry (Three Years’ Service) Roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I, various volumes
- Pennsylvania Adjutant General’s Report
- Dyer, Frederick H. Compendium of the War of the Rebellion
- Fox, William F. Regimental Losses in the American Civil War
- The Union Army, Federal Publishing Company, 1908, Volume 1