5th Regiment, Missouri Infantry (3 months, 1861) (Union)
This regiment was organized at St. Louis, Mo., May 18, 1861. It was attached to Lyons' Army of the West. Expedition from St. Louis to Potosi May 15 (Co. "A"). Moved to Springfield, Mo., June 16-17. Action at Dry Forks July 5. Expedition toward Fayette, Ark., August 3-5. Battle of Wilson's Creek August 10. March to Rolla, thence to St. Louis August 11-21. It mustered out August 27, 1861. The Colonel in charge was Charles Solomons. 
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 B - Captain Louis Gottschall
Company C - Captain Fred S. Solomon
Company D - Captain Charles Mehl
Company E - Captains Henry Richardson, Carls Stephany
Company F - Captain Alfred Arnaud
Company G - Captain Charles E. Stark
Company H - Captains William I. Chester, William I. (J.) Hawkins
Company I - Captain Charles P. Meisner
Company K - Captain Samuel A. Fladd
Lt. Col. Christopher D. Wolfe's Attached Company - Captain Robert B. Beck
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 97-114. 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 6 December 2010).