21st Regiment, Mississippi Infantry
21st Infantry Regiment was organized in October, 1861, using the 1st (Brandon's) Mississippi Infantry Battalion as its nucleus. It was mustered into Confederate service at Manassas, Virginia. The men were from the counties of Warren, Hinds, Claiborne, Lafayette, Tallahatchie, Madison, Holmes, and Union. In April, 1862, its force was 684 men, and during the war it served under the command of Generals Griffith, Barksdale, and Humphreys. The 21st participated in the campaigns of the army from the Seven Days' Battles to Gettysburg, then moved to Longstreet to fight at Chickamauga and Knoxville. After returning to Virginia it was involved in the Battles of The Wilderness, Spotsylvania, and Cold Harbor, Early's Shenandoah Valley operations, and the Appomattox Campaign. It lost 32 killed and 119 wounded during the Seven Days' Battles, had 3 killed and 56 wounded of the 200 engaged at Sharpsburg, and had 11 wounded at Fredericksburg. Its casualties at Chancellorsville were 3 killed and 25 wounded and twenty-four percent of the 424 at Gettysburg were disabled. Many were captured at Sayler's Creek, and only 4 officers and 44 men surrendered. Its field officers were Colonels William L. Brandon, Benjamin G. Humphreys, and Daniel N. Moody; Lieutenant Colonels William H. Fitzgerald and John Sims; and Major John G. Taylor. 
Regiment Companies with the County 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. It covers the major records that should be used. Additional records are described in ‘Mississippi 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.
- Mississippi in the Civil War describes many Confederate and Union sources, specifically for Mississippi, 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.
- Howell, H. Grady. Griffith's/Barksdale's/Humphey's Mississippi Brigade : Army of Northern Virginia ; a muster listing. (Carrollton, Mississippi : Pioneer Pub. Co., c2004), FHL book 976.2 M2g
- Miller, W. C. Officers and privates who enlisted in the Confederate States Army : from Wilkinson County, Mississippi, 1861-1865. (Woodville, Mississippi : Zohler's, 1903), FHL book 976.225 M29m
- National Park Service, The Civil War Soldiers and Sailors System (accessed 11 January 2011)