Overview
The 1st Ohio Infantry (Three Months’ Service) was an infantry regiment organized in Columbus, Ohio, in April 1861, in response to President Lincoln’s initial call for volunteers at the outbreak of the Civil War. The regiment served in the Union Army, primarily in the Eastern Theater. It was composed of companies drawn from various established militia units across Ohio, reflecting the state’s rapid mobilization at the war’s outset.
This unit is distinct from the 1st Ohio Infantry (Three Years’ Service).
Organization & Service
The 1st Ohio Infantry (Three Months’ Service) was organized at Columbus, Ohio, on April 18, 1861. The regiment’s companies included the Lancaster Guards, Lafayette Guards, Dayton Light Guards, Montgomery Guards of Dayton, Cleveland Grays, Hibernian Guards of Cleveland, Portsmouth Guards, Zanesville Guards, Mansfield Guards, and Jackson Guards of Hamilton. Many of these companies were well-known Ohio militia organizations prior to the war.
The regiment departed Columbus for Washington, D.C., on April 19, 1861, and was mustered into United States service at Lancaster, Pennsylvania, on April 29, 1861. Upon arrival in Washington in early May, the regiment was assigned to General Schenck’s brigade within General Tyler’s division. The 1st Ohio Infantry participated in the battle of Vienna, Virginia, and later in the First Battle of Bull Run. The regiment’s term of service expired in August 1861, and it was mustered out between August 1 and August 16, 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
- Battle of Vienna, Virginia (June 17, 1861)
- First Battle of Bull Run, Virginia (July 21, 1861)
Casualties
- Battle of Vienna: 9 killed, 2 wounded
- First Battle of Bull Run: 3 killed, 2 wounded, 2 missing
Some details are incomplete in surviving primary sources.
Field Officers & Commanders
- Colonel Alexander McDowell McCook
- Lieutenant Colonel Edwin A. Parrot
- Major John G. Hughes
Regimental Roster
The full roster of the 1st Ohio Infantry (Three Months’ Service), including officers and enlisted men, is available for researchers. The roster provides names, company assignments, and service details where recorded.
To view the complete roster, visit the 1st Ohio Infantry (Three Months’ Service) Roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I, Vol. 2
- Ohio Roster Commission, Official Roster of the Soldiers of the State of Ohio in the War of the Rebellion, Vol. 1
- 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. 2 (Federal Publishing Company, 1908)