31st Regiment, Wisconsin Infantry
The 31st Regiment, Wisconsin Infantry . Companies "A," "B," "C," "D," "E" and "F"
were organized at Prairie du Chien, Wisconsin, and were mustered in October 9 1862. Companies "G," "H," "I" and "K" were organized at Camp Utley, Racine, Wisconsin, and were mustered in December 24, 1862. It was in the Grand Review May 24. Companies "A" to "F" were mustered out June 20, and Companies "G" to "K" were mustered out July 8, 1865. 
For more information on the history of this unit, see:
- The Civil War Archive section, 31st Regiment Infantry, (accessed 21 November 2012).
- The Wikipedia Article, 31st Wisconsin Volunteer Infantry Regiment, (accessed 21 November 2012).
Companies in this Regiment with the Counties 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 company links are to rosters taken from Roster of Wisconsin Volunteers, 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 - Roster page 445.
Company B - Roster page 448.
Company C - Roster page 450.
Company D - Roster page 452.
Company E - Roster page 455.
Company F - Roster page 457.
Company G - Roster page 459.
Company H - Roster page 462.
Company I - Roster page 465.
Company K - Roster page 468.
Unassigned Recruits - Roster page 470.
- Beginning United States Civil War Research gives steps for finding information about a Civil War soldier or sailor. It covers the major records that should be used. Additional records are described in 'Wisconsin in the Civil War' and 'United States Civil War, 1861 to 1865' (see below).
- National Park Service, The Civil War Soldiers and Sailors System, is searchable by soldier's name and state. It contains basic facts about soldiers on both sides of the Civil War, a list of regiments, descriptions of significant battles, sources of the information, and suggestions for where to find additional information.
- Wisconsin in the Civil War describes many Confederate and Union sources, specifically for Wisconsin, and how to find them.. These include compiled service records, pension records, rosters, cemetery records, Internet databases, published books, etc.
- United States Civil War, 1861 to 1865 describes and explains United States and Confederate States records, rather than state records, and how to find them. These include veterans’ censuses, compiled service records, pension records, rosters, cemetery records, Internet databases, published books, etc.
- National Park Service, The Civil War Soldiers and Sailors System, (accessed 6 December 2010).
- Wisconsin. Roster of Wisconsin Volunteers, War of the Rebellion, 1861-1865 Volume II. (Madison: Democrat Printing Co., State Printers, 1886)