3rd Regiment, Missouri Cavalry (Union)
This regiment was organized at Palmyra, Mo., and St. Louis, Mo., October 15, 1861, to March 6, 1862. Attached to District of Rolla, Dept. of Missouri, to December, 1862. Cavalry Brigade, Army of Southeast Missouri, Dept. of Missouri, to June, 1863. 2nd Brigade, 1st Cavalry Division, Army of Southeast Missouri, Dept. of Missouri, to August, 1863. 2nd Brigade, 1st Cavalry Division, Arkansas Expedition, to December, 1863. 3rd Brigade, 1st Cavalry Division, Army of Arkansas, to January, 1864. 3rd Brigade, 1st Cavalry Division, 7th Army Corps, Dept. of Arkansas, to March, 1865. Separate Cavalry Brigade, 7th Army Corps, to June, 1865. 
For more information on the history of this unit, see:
- The Civil War Archive section, 3rd Regiment Cavalry, (accessed 13 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.
- 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).