The 3rd Heavy Artillery Regiment [AKA 1st Regulars or Enlisted Men, AKA 1st Infantry Regiment (Butler's)] was organized in December, 1860, with eight companies, later increased to ten. The men were recruited in Charleston, Columbia, and Cheraw, and the counties of Greenville, Lancaster, Chesterfield, and Anderson. The unit trained as infantry and artillery, and served in the Department of South Carolina, Georgia, and Florida. It took an active part in many conflicts in and around Charleston. In September, 1862, the unit contained 628 effectives and during the operations on Morris Island, July 10 to September 6, 1863, it lost 10 killed, 32 wounded, and 22 missing. In January, 1865, it was assigned to Colonel A. Rhett's Brigade and, serving as infantry, was active in the North Carolina Campaign. The unit surrendered on April 26, 1865.
Colonels Richard H. Anderson, William Butler, and John Dunovant; Lieutenant Colonels Thomas M. Baker, Barnard E. Bee, Robert De Treville, and John C. Simkins; and Majors Warren Adams and Thomas A. Huguenin.
Company A - (also called Company B and Beauregard Artillery), - many men from Edgefield District (County), Laurens District (County), Chesterfield District (County), Lancaster District (County), Charleston District (County), Darlington District (County), Spartanburg District (County), Abbeville District (County) and Calhoun Distirct (County); some men from Memphis, Tennessee and Charlote, North Carolina
Company B - (also called Company E) - Greenville District (County), Anderson District (County), Richland District (County), Columiba area.
Company C - man from various areas of South Carolina, Virginia, and Memphis, Tennessee
Company D - (also known as the Calhoun Light Infantry) - men from various areas of South Carolina, Memphis and Nashville, Tennessee and Georgia
Company E - (also called Company K and Captain Black's Company) - many men from throughout the state, especially the Charleston area
Company F - many men from throughout the state and Memphis, Tennessee
Company G - many men from throughout the state; Memphis, Tennessee, and Baltimore, Maryland
Company H - many men from the upper part of the state and a few from Memphis, Tennessee
Company I - many men from throughout the state, especially Anderson District (County); a few from Georgia
Company K - (also known as River's Battery) - many men from throughout the state