138th Pennsylvania Infantry in the American Civil War

Overview

The 138th Pennsylvania Infantry (Three Years’ Service) was an infantry regiment organized at Camp Curtin, Harrisburg, Pennsylvania, during late August and early September 1862. Composed of men from Montgomery, Adams, Bedford, and Bucks counties, the regiment served in the Union Army, primarily in the Eastern Theater. It was mustered in for a three-year term and participated in numerous campaigns and battles, including the Overland Campaign, the Shenandoah Valley Campaigns, and the final operations against Petersburg and Lee’s army.

The regiment was noted for its service in both defensive and offensive operations, including railroad guard duty, major engagements in Virginia, and the pursuit of Confederate forces in the closing days of the war. The 138th Pennsylvania Infantry mustered out on June 23, 1865, near Washington, D.C.

Organization & Service

The 138th Pennsylvania Infantry was mustered into U.S. service at Camp Curtin, Harrisburg, in late August and early September 1862. Before its organization was fully completed, the regiment moved to Baltimore on August 30, 1862, and was assigned to guard the Baltimore & Ohio Railroad, with headquarters at the Relay House. This duty continued until mid-June 1863, when the regiment moved to Harper’s Ferry and was assigned to Elliott’s Brigade, French’s Division.

Following the evacuation of Harper’s Ferry on July 1, 1863, the regiment moved to Washington, D.C., then to Frederick, Maryland, joining the pursuit of Lee’s army as part of the 3rd Corps. The 138th was under fire at Wapping Heights but not actively engaged. During the fall, it participated in marches and counter-marches of the Virginia campaign, including action at Brandy Station and the Mine Run Campaign at Locust Grove, where it suffered significant casualties and displayed notable gallantry.

After wintering at Brandy Station, the regiment joined the spring campaign of 1864, attached to Seymour’s Brigade, Rickett’s (3rd) Division, 6th Corps. It sustained heavy losses at the Wilderness and participated in actions at Spotsylvania and Cold Harbor. The regiment then crossed the James River, served in the trenches at Bermuda Hundred, and later joined the 6th Corps before Petersburg. It took part in the movement on the Weldon Railroad at Reams’ Station and was engaged at Monocacy on July 9, 1864, suffering further losses.

The 138th Pennsylvania Infantry participated in maneuvers between Washington and the Shenandoah Valley, supporting cavalry at Smithfield and engaging at Opequon and Fisher’s Hill. It was present at Cedar Creek in October 1864, then encamped at Philadelphia and Winchester. In December, the regiment moved to Petersburg and served as garrison for Fort Dushane, receiving a new stand of colors from citizens of Norristown and Bridgeport, Pennsylvania. In April 1865, it rejoined the corps, participated in the final assault on Petersburg, and joined the pursuit of Lee’s army, fighting its last battle at Sailor’s Creek. After Lee’s surrender, the regiment marched to Danville, Virginia, then returned to Richmond and Washington, where it was mustered out on June 23, 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

  • Baltimore & Ohio Railroad guard duty (1862–1863)
  • Harper’s Ferry (June–July 1863)
  • Pursuit of Lee (July 1863)
  • Wapping Heights
  • Brandy Station
  • Mine Run Campaign (Locust Grove)
  • Wilderness
  • Spotsylvania
  • Cold Harbor
  • Bermuda Hundred
  • Petersburg operations
  • Reams’ Station
  • Monocacy (July 9, 1864)
  • Smithfield
  • Opequon (Third Winchester)
  • Fisher’s Hill
  • Cedar Creek
  • Final Petersburg assault (April 2, 1865)
  • Pursuit of Lee
  • Sailor’s Creek

Casualties

  • Total enrollment: 955
  • Killed in action or died of wounds: 94
  • Died of disease and accident: 54
  • Wounded: 339
  • Missing: 31
  • Captured: 48

Casualty figures are based on regimental and state reports. If discrepancies exist in other sources, they are not reflected here.

Field Officers & Commanders

  • Colonel Charles L. K. Sumwalt
  • Colonel M. R. McClennan
  • Lieutenant Colonel M. R. McClennan
  • Lieutenant Colonel Lewis A. May
  • Major Lewis A. May
  • Major Simon Dickerhoof

Regimental Roster

The full roster of the 138th 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 138th Pennsylvania Infantry (Three Years’ Service) Roster page.

Sources & References

  • Official Records of the Union and Confederate Armies, Series I, Volumes 27, 29, 36, 40, 43
  • Pennsylvania State 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, Vol. 1
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