8th Regiment, Missouri Infantry (Union)
This regiment (also called 8th Regiment, Volunteer Missouri Infantry) was organized at St. Louis, Mo., June 12 to August 14, 1861. It was attached to Cape Girardeau, Mo., to September, 1861. District of Paducah, Ky., to February, 1862. 5th Brigade, 2nd Division, District of Cairo, February, 1862. 1st Brigade, 3rd Division, Army of the Tennessee, to May, 1862. 1st Brigade, 5th Division, Army of the Tennessee, to July, 1862. 1st Brigade, 5th Division, District of Memphis, Tenn., to November, 1862. 1st Brigade, 5th Division, District of Memphis, 13th Army Corps (Old), Dept. of the Tennessee, to December, 1862. 1st Brigade, 2nd Division, Right Wing 13th Army Corps, December, 1862. 1st Brigade, 2nd Division, Sherman's Yazoo Expedition, to January, 1863. 1st Brigade, 2nd Division. 15th Army Corps, Army of the Tennessee, to August, 1865. Mustered out August 14, 1865. 
For more information on the history of this unit, see:
- The Civil War Archive section, 8th Regiment Infantry, (accessed 25 July 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.
Company A - Captain George M. Crane, Captain William A. Johnson, Captain John McDonald - enrolled in St. Louis, St. Louis County
Company B - Captain William Hill - enrolled in Peoria County
Company C - Captain Charles McDonald, Captain Thomas L. Morgan - enrolled in St. Louis, St. Louis County
Company D - Captain John B. Cole, Captain Morgan Potts, Captain Giles A. Smith - enrolled in St. Louis, St. Louis County
Company E - Captain Sidney W. Ainsworth, Captain Dennis T. Kirby, Captain John McDonald, Captain Nelson Patterson - enrolled in Bloomington, McLean County
Company F - Captain Alexander A. Jameson - enrolled in St. Louis, St. Louis County
Company G - Captain David P. Gyer, Captain Henry C. Moffatt, Captain William C. Russell, Cptain Alonzo S. Sterling - enrolled in Chicago, Cook County
Company H - Captain Alexander Hart, Captain George B. Swartwoul, Captain John W. White - enrolled in Peoria County
Company I - Captain Alexander Hart, Captain William H. McGowan - enrolled in Canton, Fulton County
Company K - Captain Hugh Neill, Captain Edward N. Seibel - enrolled in Warsaw County
The information about the companies and counties is from Kenneth E. Weant's book, Civil War Records, Missouri Volunteer Infantry, Volume 2, Three Year Volunteer Regiments 4-10, (Arlington, Texas: K.E. Weant, c2011), pages 76-92. FHL 977.8 M2wkv v. 2
- 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 'Missouri 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.
- Missouri in the Civil War describes many Confederate and Union sources, specifically for Missouri, 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).