11th Regiment, Missouri Infantry (Union)
This regiment was organized at St. Louis, Mo., August, 1861. It moved to Cape Girardeau, Mo., August 16, 1861. Then it was attached to Military District of Cairo, Ill., Dept. of Missouri, to February, 1862. 2nd Brigade, 1st Division, Army of Mississippi, to March, 1862. 2nd Brigade, 5th Division, Army of Mississippi, to April, 1862. 1st Brigade, 3rd Division, Army of Mississippi, to April, 1862. 2nd Brigade, 2nd Division, Army of Mississippi, to November, 1862. 2nd Brigade, 8th Division, Left Wing 13th Army Corps (Old), Dept. of the Tennessee, to December, 1862. 2nd Brigade, 8th Division, 16th Army Corps, to April, 1863. 2nd Brigade, 3rd Division, 15th Army Corps, Army of the Tennessee, to December, 1863. 2nd Brigade, 1st Division, 16th Army Corps, to December, 1864. 2nd Brigade, 1st Division (Detachment), Army of the Tennessee, Dept. of the Cumberland, to February 1865. 2nd Brigade, 1st Division, 16th Army Corps (New), Military Division West Mississippi, to August, 1865. District of Alabama to December, 1865. 
The 11th Regiment, Volunteer Missouri Infantry was enrolled between July 7 1861 and July 30 1861.
They were ordered into service between August 3 1861 and August 16 1861. The Regiment was discharged on January 15 1866. The Colonel's ín charge were Colonel Eli Bowyer, Colonel Joseph A. Mower, Colonel Joseph B. Plummer, and Colonel Andrew J. Webber. 
For more information on the history of this unit, see:
- The Civil War Archive section, 11th 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 Cyrenus Elliott, Captain Leonidas Horney, Captain Constantine McMahan and Captain Menomen O'Donnall - Sumner,Lawrence, Illinois.
Company B - Captain T. F. (P.) Followell (Fallowell), Captain Jessie B. Lloyd (Floyd) and Captain Andrew A. Weber - Sagaman, Illinois
Comany C - Captain Modeto J. Green and Captain Moses Warner - Springfield, Sagaman, Illinois.
Company D - Captain Clark K. Handee, Captain George W. Henry and Captain James A. Lott - Sumner, Lawrence, Illinois.
Company E - Captain Abner B. Bail, Captain Charles Hollister, Captain Benjamin F. Livingstonand Captain Levi D. Roney - Olney, Richland, Illinois.
Company F - Captain William W. Clelland and Captain Charles Smith - Flora,Clay, Illinois.
Company G -Captain Edwin R. Applegate, and Captain William C. J. Mieur - Lawrence , Illinois.
Company H - Captain William W. Boatright - Sumner, Lawrence, Illinois.
Company I - Captain George C. Adams and Charles H. Osgood - Bethel, Morgan, Illinois.
Company K - Captain William S. Stewart - Franklin, 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 93-94. 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.
- Belcher, Dennis W. The 11th Missouri volunteer infantry in the Civil war : a history and roster. (Jefferson, North Carolina : McFarland and Co., c2011),World Cat