Overview
The 21st Illinois Infantry (Three Years’ Service) was an infantry regiment from Illinois that served in the Union Army during the American Civil War. Organized at Mattoon, Illinois, the regiment entered federal service on June 28, 1861, and served primarily in the Western Theater. The unit is notable for having Ulysses S. Grant as its first colonel and for its participation in several major campaigns and battles, including Perryville, Stone’s River, Chickamauga, Atlanta, and Nashville.
This regiment should not be confused with any other Illinois infantry units of different service terms.
Organization & Service
The 21st Illinois Infantry (Three Years’ Service) was initially called into state service under the “Ten Regiment Bill” and rendezvoused at Mattoon on May 9, 1861. It was mustered into state service for 30 days on May 15, 1861, by Captain U. S. Grant, and was known as the 7th Congressional District Regiment during that period. The companies were drawn from Macon, Cumberland, Piatt, Douglas, Moultrie, Edgar, Clay, Clark, Crawford, and Jasper counties. On June 28, 1861, the regiment was mustered into United States service for three years.
After federal muster, the regiment was ordered to Missouri, stationed at Ironton until October 17, 1861, and participated in operations at Fredericktown. In May 1862, the 21st Illinois moved to the front lines and was present during the final days of the Siege of Corinth as part of the 2nd Brigade, 4th Division, Left Wing, Army of the Mississippi. The regiment fought at Perryville, Kentucky, in October 1862, and joined the pursuit of Confederate forces as far as Crab Orchard, then marched through Kentucky and Tennessee, arriving near Nashville in November.
During the winter of 1862–63, the regiment was attached to the 2nd Brigade, 1st Division, 20th Army Corps, and participated in the skirmish at Knob Gap and the engagement near Murfreesboro, where it charged and temporarily captured a Confederate battery. At the Battle of Stone’s River, the 21st Illinois suffered heavy casualties. The regiment was also engaged at Liberty Gap in June 1863, and at Chickamauga in September, where it lost 238 officers and men over two days of fighting.
In January 1864, the regiment moved to Ooltewah, Tennessee, and reenlisted as a veteran organization in March. After furlough, it rejoined the army before Kennesaw Mountain and participated in the Atlanta Campaign, including the battles before Atlanta and at Jonesboro. Later in 1864, the regiment was transferred to Tennessee, where it fought at Columbia and took a prominent role in the Battle of Nashville, capturing a battery and prisoners. In the spring of 1865, the 21st Illinois was sent to Texas, camping near New Orleans before moving to Matagorda Bay, Victoria, and San Antonio. The regiment was mustered out at San Antonio on December 16, 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
- Fredericktown, Missouri (October 1861)
- Siege of Corinth (May 1862)
- Perryville, Kentucky (October 1862)
- Knob Gap (December 1862)
- Murfreesboro / Stone’s River (December 1862 – January 1863)
- Liberty Gap (June 1863)
- Chickamauga (September 1863)
- Atlanta Campaign (June–September 1864)
- Jonesboro (September 1864)
- Columbia, Tennessee (November 1864)
- Nashville (December 1864)
Casualties
According to Fox’s Regimental Losses and official reports, the 21st Illinois Infantry (Three Years’ Service) suffered significant casualties:
- Killed or mortally wounded: 6 officers, 110 enlisted men
- Died of disease: 1 officer, 134 enlisted men
- Total deaths: 251
Field Officers & Commanders
- Colonel Ulysses S. Grant
- Colonel John W. S. Alexander
- Lieutenant Colonel John W. S. Alexander
- Lieutenant Colonel George W. Peck
- Lieutenant Colonel Warren E. McMakin
- Lieutenant Colonel James E. Calloway
- Lieutenant Colonel William H. Jamison
- Major Warren E. McMakin
- Major James E. Calloway
- Major William H. Jamison
- Major John L. Wilson
Regimental Roster
The complete roster of the 21st Illinois Infantry (Three Years’ 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 throughout its federal service.
To view the full roster, visit the 21st Illinois Infantry (Three Years’ Service) Roster page.
Sources & References
- Official Records of the Union and Confederate Armies, Series I, Vol. 3, 16, 23, 30, 38, 45
- Report of the Adjutant General of the State of Illinois
- Dyer, Frederick H. Compendium of the War of the Rebellion
- Fox, William F. Regimental Losses in the American Civil War
- Contemporary regimental and state histories