125th Pennsylvania Infantry in the American Civil War

Overview

The 125th Pennsylvania Infantry (Nine Months’ Service) was an infantry regiment raised primarily in Blair and Huntingdon counties, Pennsylvania. Organized for Union service during the American Civil War, the regiment mustered in at Harrisburg on August 16, 1862, for a nine months’ term. The unit served in the Eastern Theater, participating in major campaigns of the Army of the Potomac during its brief but active service.

The regiment is noted for its heavy engagement at the Battle of Antietam, where it suffered significant casualties and demonstrated notable steadiness under fire. Its service included both combat operations and important guard duties in the defenses of Washington and along key transportation routes.

Organization & Service

The 125th Pennsylvania Infantry (Nine Months’ Service) was organized at Harrisburg and mustered into United States service on August 16, 1862. The regiment was immediately sent to Washington, D.C., where it was assigned by General Silas Casey to a provisional brigade under Colonel Jacob Higgins. Initial duties included guard assignments at Hunter’s Chapel and later at Fort Bernard, Virginia.

On September 6, 1862, the regiment moved to Rockville, Maryland, where it joined the main Union army and was attached to the 1st Brigade, 1st Division, XII Corps (then known as Banks’ Corps), under the commands of Generals Mansfield and Williams. The regiment’s first major combat occurred at the Battle of Antietam on September 17, 1862, where it was heavily engaged and incurred substantial losses. Following Antietam, the 125th Pennsylvania encamped at Pleasant Valley, Maryland, and Loudoun Heights.

The regiment subsequently moved toward Fredericksburg, Virginia, but arrived too late to participate in the battle there. It then returned to Fairfax Station and took part in the “Mud March” in January 1863. Afterward, the regiment established winter quarters near Stafford Court House. On March 24, 1863, it was reassigned to the 2nd Brigade, 2nd Division, XII Corps, and posted at Acquia Creek. The regiment was active at the Battle of Chancellorsville in May 1863, after which it returned briefly to Acquia Creek. The 125th Pennsylvania Infantry was mustered out of service at Harrisburg on May 18-19, 1863.

Engagements & Campaigns

• Defenses of Washington, D.C. (August–September 1862)
• Maryland Campaign (September 1862)
• Battle of Antietam (September 17, 1862)
• Encampment at Pleasant Valley and Loudoun Heights (Fall 1862)
• March to Fredericksburg (December 1862)
• “Mud March” (January 1863)
• Battle of Chancellorsville (May 1–5, 1863)

Casualties

At the Battle of Antietam, the 125th Pennsylvania Infantry suffered approximately 150 casualties. Detailed figures for total killed, wounded, and died of disease during the regiment’s nine months’ service are not fully specified in available primary sources.

Field Officers & Commanders

• Colonel Jacob Higgins
• Lieutenant Colonel Jacob Szink
• Major John J. Lawrence

Regimental Roster

The complete roster of the 125th Pennsylvania Infantry (Nine Months’ Service), including officers and enlisted men, is available for genealogical and historical research. The roster provides names, ranks, and service details for members of the regiment.

To view the full roster, visit the 125th Pennsylvania Infantry (Nine Months’ Service) Roster page.

Sources & References

• Official Records of the Union and Confederate Armies, Series I, Vol. XIX, Part 1
• 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, Vol. 1