115th Pennsylvania Infantry in the American Civil War

Overview

The 115th Pennsylvania Infantry (Three Years’ Service) was an infantry regiment organized in Pennsylvania for service in the Union Army during the American Civil War. Recruitment drew primarily from Philadelphia, Cambria, Lebanon, and Lancaster counties. The regiment was mustered into United States service early in 1862 at Diamond Cottage, Camden, New Jersey, and served in the Eastern Theater as part of the Army of the Potomac. The 115th Pennsylvania participated in many major campaigns and engagements, including the Peninsula Campaign, Second Bull Run, Fredericksburg, Chancellorsville, Gettysburg, and the Overland Campaign.

Organization & Service

The 115th Pennsylvania Infantry was organized early in 1862, with mustering taking place at Diamond Cottage, Camden, New Jersey, for a three-year term. The regiment initially performed guard duty over prisoners at Harrisburg until June 25, 1862, after which it moved to join the Army of the Potomac on the Virginia Peninsula. Upon arrival at Harrison’s Landing on July 4, 1862, the regiment was assigned to the 3rd Brigade, Hooker’s Division, 3rd Corps.

The 115th Pennsylvania saw its first combat at Malvern Hill in August 1862, then participated in the actions at Kettle Run and the Second Battle of Bull Run. It was in support at Chantilly before being ordered to Washington, D.C., where it remained until November. The regiment then rejoined the army, encamping at Catlett’s Station, Bristoe Station, Manassas Junction, and Falmouth through November and early December. It participated in the Battle of Fredericksburg and the subsequent “Mud March,” returning to Falmouth until the Chancellorsville Campaign in May 1863, where it sustained heavy losses.

After Chancellorsville, the regiment again encamped at Falmouth before marching north with the army to Pennsylvania. The 115th arrived at Gettysburg on the evening of July 1, 1863, and was initially posted in advance of the line near Round Top on July 2. Forced to withdraw to the main line, the regiment withstood repeated attacks and suffered significant casualties. Following Gettysburg, the regiment moved south with the army, engaging at Wapping Heights and encamping at Bealeton Station. In September, it camped at Culpeper, and on October 15, 1863, fought at McLean’s Ford. The regiment also saw action at Kelly’s Ford and Mine Run before wintering at Brandy Station.

In 1864, the 115th Pennsylvania served with Birney’s Division of Hancock’s Corps, fighting in the Wilderness, Spotsylvania, North Anna, Totopotomy, Cold Harbor, and Petersburg. Due to heavy losses, the regiment was consolidated with the 190th Pennsylvania Infantry by special order on June 22, 1864. The field and staff officers were mustered out on June 23, 1864; company officers remained in service, and the enlisted men were mustered out with the 190th Pennsylvania at Washington on June 28, 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

  • Malvern Hill (August 1862)
  • Kettle Run
  • Second Bull Run
  • Chantilly (support)
  • Fredericksburg
  • Mud March
  • Chancellorsville
  • Gettysburg
  • Wapping Heights
  • McLean’s Ford
  • Kelly’s Ford
  • Mine Run
  • Wilderness
  • Spotsylvania
  • North Anna
  • Totopotomy
  • Cold Harbor
  • Petersburg

Casualties

Specific casualty figures for the 115th Pennsylvania Infantry are not fully detailed in all primary sources. The regiment sustained heavy losses at Chancellorsville and Gettysburg. Total losses, including killed, wounded, and missing, are not consistently reported in available records.

Field Officers & Commanders

  • Colonel Robert E. Patterson
  • Colonel F. A. Lancaster
  • Colonel William C. Ward
  • Lieutenant Colonel Robert Thompson
  • Lieutenant Colonel William C. Ward
  • Lieutenant Colonel John P. Dunne
  • Major F. A. Lancaster
  • Major John P. Dunne
  • Major William A. Reilly

Regimental Roster

The full roster of the 115th Pennsylvania Infantry (Three Years’ Service), including officers and enlisted men, is available on the regiment’s roster page. This resource provides names, ranks, and additional service details valuable for genealogical and historical research.

To view the complete roster, visit the 115th Pennsylvania Infantry (Three Years’ Service) Roster page.

Sources & References

  • Official Records of the Union and Confederate Armies, Series I, various volumes and parts
  • Pennsylvania Adjutant General’s Report
  • Dyer, Frederick H., A 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
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