138th Regiment, Illinois Infantry (100 days, 1864)
The 138th regiment, Illinois Infantry ( 100 days, 1864) was organized at Camp Wood, Quincy, Illinois, and mustered in for 100 days June 21, 1864. It mustered out October 14, 1864. 
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.
- 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.
- Organized at Mattoon, Illinois, and mustered in for 100 days June 6, 1864. Mustered out September 28, 1864.