Overview
The 105th Pennsylvania Infantry (Three Years’ Service) was an infantry regiment organized in Pittsburgh, Pennsylvania, during September and October 1861. Composed primarily of men from Jefferson, Clarion, and Clearfield counties, the regiment served in the Union Army throughout the Eastern Theater of the American Civil War. The 105th Pennsylvania was mustered into federal service for a three-year term and participated in many major campaigns and battles, earning a reputation for steadfastness and gallantry.
The regiment was attached to the 1st Brigade, 1st Division, 3rd Corps, Army of the Potomac, and later served with the 10th Corps. Its service included notable actions from the Peninsula Campaign through the final operations in Virginia, and it was present at the Grand Review in Washington, D.C., before mustering out in July 1865.
Organization & Service
The 105th Pennsylvania Infantry was organized at Pittsburgh in September and October 1861 and mustered into United States service for three years. Shortly after organization, the regiment was ordered to Washington, D.C., in October 1861 and encamped near Alexandria, Virginia. It was assigned to the 1st Brigade, 1st Division, 3rd Corps, Army of the Potomac.
The regiment participated in the Peninsula Campaign, including the siege of Yorktown (April–May 1862), and fought at Williamsburg and Fair Oaks. At Fair Oaks, the regiment held its position under difficult circumstances, with three companies detached and fighting alongside the 57th Pennsylvania. The 105th Pennsylvania was subsequently engaged at Glendale and Malvern Hill, suffering significant losses from combat and disease, reducing its effective strength to fewer than 100 men by the time it reached Harrison’s Landing.
During operations along the railroad between Manassas and Warrenton Junction, Companies B, G, and H were captured. The regiment fought at Bristoe Station (August 29, 1862) and the Second Battle of Bull Run (August 30, 1862), where it again sustained heavy casualties and was commended by General Kearny for its conduct. After a period in Washington, the regiment moved to Falmouth, Virginia, in November 1862 and fought at Fredericksburg in December.
The winter of 1862–1863 was spent near Brandy Station. The regiment was engaged at Chancellorsville in May 1863, where several members received the Kearny Medal of Honor. After time at Banks Ford, the regiment marched north and fought at Gettysburg in July 1863, suffering further losses. It then participated in the Mine Run Campaign, including actions at Auburn, Kelly’s Ford, and Locust Grove, before wintering again at Brandy Station.
On December 28, 1863, nearly the entire regiment reenlisted as veteran volunteers. In 1864, the 105th Pennsylvania fought in the Wilderness and Spotsylvania battles, then moved with the Army of the Potomac to Petersburg, participating in the operations of the 10th Corps and actions along the Weldon Railroad. On September 5, 1864, the remaining men of the 63rd Pennsylvania were consolidated into the regiment, and in March 1865, about 300 new recruits joined. The regiment was actively engaged at Sailor’s Creek in April 1865, then returned to Alexandria and participated in the Grand Review. The 105th Pennsylvania Infantry was mustered out at Washington, D.C., on July 11, 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
- Siege of Yorktown (April–May 1862)
- Battle of Williamsburg
- Battle of Fair Oaks
- Battle of Glendale
- Battle of Malvern Hill
- Bristoe Station (August 29, 1862)
- Second Battle of Bull Run (August 30, 1862)
- Battle of Fredericksburg
- Battle of Chancellorsville
- Battle of Gettysburg
- Auburn, Kelly’s Ford, Locust Grove (Mine Run Campaign)
- Battle of the Wilderness
- Battle of Spotsylvania
- Operations before Petersburg
- Weldon Railroad operations
- Battle of Sailor’s Creek
Casualties
Out of a total enrollment of 2,040 men, the 105th Pennsylvania Infantry lost 309 members by death from wounds or disease. An additional 199 were reported missing. These figures are based on regimental and state reports; specific breakdowns by battle or cause may vary in different sources.
Field Officers & Commanders
- Colonel Amor A. McKnight
- Colonel William W. Corbett
- Colonel Calvin A. Craig
- Colonel James Miller
- Lieutenant Colonel William W. Corbett
- Lieutenant Colonel Calvin A. Craig
- Lieutenant Colonel J. W. Greenawalt
- Lieutenant Colonel L. B. Duff
- Lieutenant Colonel Oliver C. Reddie
- Major Mungo M. Dick
- Major J. W. Greenawalt
- Major Levi B. Duff
- Major John C. Conser
- Major James Miller
Regimental Roster
The complete roster of the 105th Pennsylvania Infantry (Three Years’ Service), including officers and enlisted men, is available on the regiment’s roster page. This roster provides names, ranks, and additional service details for those who served in the unit.
To view the full roster, visit the 105th Pennsylvania Infantry (Three Years’ Service) Roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I, various volumes and parts (Army of the Potomac, 1861–1865)
- Pennsylvania Adjutant General’s Report, annual reports 1861–1865
- Dyer, Frederick H., A Compendium of the War of the Rebellion
- Fox, William F., Regimental Losses in the American Civil War
- The Union Army, Vol. 1 (Federal Publishing Company, 1908)