Overview
The 55th Indiana Infantry (Three Months’ Service) was an infantry regiment organized in Indiana for Union service during the American Civil War. The regiment was mustered in at Indianapolis on June 16, 1862, under special orders for a three-month term. Its primary duties included guarding Confederate prisoners and participating in defensive operations during the summer of 1862.
This unit served exclusively in the Western Theater and was notable for its role in guarding prisoners at Camp Morton and for its deployment to Kentucky during the Confederate invasion led by General Kirby Smith.
Organization & Service
The 55th Indiana Infantry (Three Months’ Service) was organized at Indianapolis in June 1862. Upon mustering in, the regiment was immediately assigned to guard duty at Camp Morton, where it oversaw Confederate prisoners captured at Fort Donelson and other engagements. In August 1862, as Confederate forces under General Kirby Smith advanced into Kentucky, the regiment was ordered to Kentucky to assist in the defense of the state.
The 55th Indiana remained on duty in Kentucky, performing various defensive and security tasks, until the expiration of its service term. The regiment was mustered out at Indianapolis in September 1862. The original strength of the regiment was 639 men, with an additional 19 recruits joining during its service, bringing the total to 658. Losses included 4 deaths, and 19 men were unaccounted for at muster out.
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
- Guard duty at Camp Morton, Indiana (June–August 1862)
- Operations in Kentucky during the Confederate invasion by General Kirby Smith (August–September 1862)
Casualties
- Killed or died of disease: 4
- Unaccounted for at muster out: 19
- Total enrollment: 658
Field Officers & Commanders
- Lieutenant Colonel John R. Mahan
- Major James B. Mulkey
Regimental Roster
The full roster of the 55th Indiana Infantry (Three Months’ Service), including officers and enlisted men, is available for genealogical and historical research. This roster provides names, ranks, and additional service details where available.
To view the complete roster, visit the 55th Indiana Infantry (Three Months’ Service) Roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I, relevant volumes
- Indiana Adjutant General’s Report
- Dyer, Frederick H., A Compendium of the War of the Rebellion
- Federal Publishing Company, The Union Army, Vol. 3 (1908)