Overview
The 12th Pennsylvania Infantry (Three Months’ Service) was an infantry regiment organized in Pennsylvania for Union service during the early months of the American Civil War. The regiment was mustered into United States service at Harrisburg on April 25, 1861, for a term of three months. It was composed primarily of companies recruited in Pittsburgh, with additional companies from New Castle and Washington County. The regiment served in the Eastern Theater and was tasked with important guard duties during its brief service.
Organization & Service
The 12th Pennsylvania Infantry (Three Months’ Service) was organized at Harrisburg, Pennsylvania, on April 25, 1861. The regiment consisted of six companies from Pittsburgh, two from New Castle, and two from Washington County. Colonel David Campbell commanded the regiment, with Lieutenant Colonel Norton McGiffin and Major Alexander Hayes as principal officers.
After mustering in, the regiment spent several weeks stationed at York, Pennsylvania. On May 25, 1861, it was ordered to guard the Northern Central Railroad between the Pennsylvania state line and Baltimore, Maryland. Regimental headquarters were established at Cockeysville, Maryland. The regiment’s primary duty was to protect this vital transportation route from potential Confederate disruption, a task it performed until the end of its service. The 12th Pennsylvania Infantry was mustered out at Harrisburg on August 5, 1861.
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
- Guard duty along the Northern Central Railroad between the Pennsylvania state line and Baltimore, Maryland (May–August 1861)
Casualties
Specific casualty figures for the 12th Pennsylvania Infantry (Three Months’ Service) are not detailed in primary sources. The regiment primarily performed guard duty and did not participate in major engagements during its term of service.
Field Officers & Commanders
- Colonel David Campbell
- Lieutenant Colonel Norton McGiffin
- Major Alexander Hayes
Regimental Roster
The full roster of the 12th Pennsylvania Infantry (Three Months’ Service), including officers and enlisted men, is available for genealogical and historical research. For a complete listing of soldiers who served in this regiment, please visit the regimental roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I
- Pennsylvania Adjutant General’s Report
- Dyer, Frederick H., A Compendium of the War of the Rebellion
- Federal Publishing Company, The Union Army, Vol. 1 (1908)