37th Regiment, Illinois Infantry
The 37th Regiment, Illinois Infantry was organized at Chicago, Illinois, and mustered in September 18, 1861. It moved to Houston July 17. Mustered out May 15, 1866. 
Companies in this Regiment with County of Origin
Men often enlisted in a company recruited in the counties where they lived though not always. After many battles, companies might be combined because so many men were killed or wounded. However if you are unsure which company your ancestor was in, try the company recruited in his county first.
The following counties of origin are taken from the Adjutant General's Report, found on the Illinois Civil War Rosters web site. Roster pages are from the same report found on the Internet Archives web site. The rosters show the men who served in each regiment, their residences, dates of enlistment and mustering out, and other remarks.
- Company A - many men from Rock Island and Mercer counties - Rock Island and Mercer counties web sites - Roster, vol. 3, pages 39-42.
- Company B - many men from Stark and Henry counties - Stark and Henry county web sites - Roster, vol. 3, pages 43-45.
- Company D - many men from Cook County and the state of Michigan - Cook County web site - Roster, vol. 3, pages 48-51.
- Company G - many men from Cook and McLean counties - Cook and McLean county web sites - Roster, vol. 3, pages 57-60.
- Company H - many men from Rock Island County - Rock Island County web site - Roster, vol. 3, pages 60-63.
- Company K - many men from Vermilion County - Vermilion County web site - Roster, vol. 3, pages 66-69.
- Unassigned Recruits - Roster, vol. 3, page 69.
- Civil War Soldiers and Sailors System, (accessed 30 Dec. 2010) can be searched by soldier's name or by regiment; includes regimental rosters and additional history of the regiment.
- Illinois Civil War Rosters from the Adjutant General's Report, 37th Regiment (accessed 10 May 2011) includes rosters of all the regiments and information on the different companies in each regiment.
- Illinois State Archives - Illinois Civil War Muster and Descriptive Rolls Database (accessed 14 June 2011). Search by residence, unit, regiment, company or soldier.
- National Park Service, The Civil War Soldiers and Sailors System, (accessed 10 May 2011).