3rd Regiment, Missouri Infantry (3 months, 1861) (Union)
This regiment was organized at St. Louis, Mo., April 22, 1861. It ws attached to Lyons' Army of the West. Capture of Camp Jackson, St. Louis, May 10. March to Rolla, thence to Springfield, Mo., June 13-24. March to Neosho June 26-30. Retreat to Mt. Vernon, thence to Springfield, Mo., July 5-11. Action at Carthage July 5. Battle of Wilson's Creek August 10. Retreat to Rolla, thence to St. Louis August 11-21. It mustered out September 4, 1861. The Colonel in charge was Franz Sigel. 
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 John Fred Cramer
Company B - Captain Henry Zeis
Company C - Captain Jacob Hartmann
Company D - Captain Augustus Hackman
Company E - Captain John Emil Strodtman
Company F - Captains Constantine Blandousky, Hugh Gollmer
Company G - Captain Adolph Dengler
Company H - Captain George D. Friedlein
Company I - Captain Charles H. Manhart
Company K - Captain Theodore Maumain
Rifle Battalion, Company A - Captains Joseph Indest and Henry Tannhauser
Rifle Battalion, Company B - Captains Joseph Conrad and Fred Schreiner
The information about the counties is from Kenneth E. Weant's book, Civil War Records, Missouri Volunteer Infantry, Volume 1, Three Month Volunteer Regiments, 1-5 and Three Year Volunteer Regiments 1-3, (Arlington, Texas: K.E. Waant, c2011), pages 59-74. FHL book 977.8 M2wkv. Partial rosters are also included.
- 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 11 January 2011).