See main article: Illinois in the American Civil War.
In recognition of Illinois’ six regiments' service in the Mexican War, regimental numbers for infantry in the Civil War began at seven.
Named Units
1st Regiment Illinois Volunteer Light Artillery
2nd Regiment Illinois Volunteer Light Artillery
Named Units
Report of the Adjutant General of the State of Illinois. This series of books give an overview of all military units provided the State of Illinois and listing of rosters of each unit.