17th Regiment, Missouri Infantry (Union)
This regiment was organized at St. Louis, Mo., August, 1861. It was attached to Army of the West to January, 1862. 2nd Brigade, Army of Southwest Missouri, to March, 1862. 1st Brigade, 1st Division, Army of Southwest Missouri, to May, 1862. 3rd Division, Army of Southwest Missouri, to July, 1862. District of Eastern Arkansas, Dept. of Missouri, to November, 1862. 1st Brigade, 1st Division, District of Eastern Arkansas to December, 1862. 1st Brigade, 11th Division, Right Wing 13th Army Corps (Old), Dept. of the Tennessee, to December, 1862. 2nd Brigade, 4th Division, Sherman's Yazoo Expedition, to January, 1863. 2nd Brigade, 1st Division, 15th Army Corps, Army of the Tennessee, to September, 1863. 1st Brigade, 1st Division, 15th Army Corps, to December, 1863. 3rd Brigade, 1st Division, 15th Army Corps, to December, 1864. 
For more information on the history of this unit see:
The Civil War Archive section, 17th 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 August William Busche, Captain John George Langguth and Captain Theodore Weller - St. Louis, Missouri.
Company B - Captain William, Andre, and Captain Julius Muller (Mueller) - St. Louis, Missouri.
Company C - Captain Adolphus Boettscher - St. Louis, Missouri.
Company D - Captain Louis Darmstrat, Captain Paul Morensky, Captain Fred Niegemann and Captain Herman O. Rettburg - St. Louis, Missouri.
Company E - Captain August Fischer (Fisher), Captain Joseph Fries and Captain William Fuchs -St. Louis, Missouri.
Company F - Captain Charles Bowcking, Captain Hugo Golmer (Guillmer) and Captain Francis Gulde -St. Louis, Missouri.
Company G - Captain John A. Schaub - St. Louis, Missouri.
Company H - Captain Adolph Ehlert and Captain John G. Kaegi - St. Louis, Missouri.
Company I - Captain Charles Reis - Cincinnati, Hamilton, Ohio
Company K - Captain Charles Bruns and Captain Adolph Schill -St Louis, Missouri.
The information about the companies and counties is from Kenneth E. Weant's book, Civil War Records, Missouri Volunteer Infantry, Volume 3, Three Year Volunteer Regiments 11-18, 25, (Arlington, Texas: K.E. Weant, c2011), pages 125-139. 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 21 Sept 2011).