The 51st Regiment was organized about August 1861 with ten companies, A to K. Company L enlisted August 22, 1861, and was assigned to the 23rd Battalion Virginia Infantry in January 1862. The 51st was reorganized in May, 1862.

Co. A, Capt. John P. Wolfes Co.; formerly called Co. I; enlisted July 16, 1861, for one year; reorganized May 20, 1862. Captains: John P. Wolfe (to Major, 1863), Daniel Hoge Bruce.

Co. B, Wharton Grays; formerly called Co. H; enlisted July 31, 1861 for one year; joined regimental August 14, 1861; reorganized May 6, 1862. Captains: David Pierce Graham (to Major, 1863), William Hanson Tate (killed May 15, 1864), David S. Allison (died in service).

Co. C, Wythe Rifles; Wythe County; formerly called Co. E; enlisted July 20, 1861, for one year; reorganized May 3, 1862. Captains: William H. Cook, William A. Yonce (to Major, April 23 , 1864), Jehiel F. Umbarger.

Co. D, Capt. D. Lee Ross Co.; formerly called Co. C; enlisted June 14, 1861, for one year; reorganized May 5, 1862. Captains: David Lee Ross (to April 1862), William T. Akers (to Major, 1864), Rufus J. Woolwine.

Co. E, Nelson Volunteers; Nelson County; formerly called Co. B; enlisted July 1, 1861, for one year; reorganized May 7, 1862. Captains: John Turner Dillard (to April 1862), Thomas J. Graves ( resigned 1862), Austin J. Graves (resigned 1863), Josephus Mills.

Co. F, Bland Tigers; Bland County; formerly called Co. K; enlisted June 26, 1861, for one year; reorganized May 20, 1862. Captains: Samuel H. Newberry (not re-elected; reappointed May 29, 1863), William G. Repass (resigned February 6, 1863).

Co. G, Floyd Game Cocks; (also known as Floyd Game Bucks), Floyd County; enlisted June 29, 1861, for one year; reorganized July 1, 1861. Captain: James William Henry.

Co. H, Capt. Granville R. Conners Co. ; formerly called Company F; enlisted July 2, 1861, for one year; reorganized May 23, 1862. Captains: Granville R. Conner (to April 1862), William G. Price (wounded; captured).

Co. I, Capt. Ezekiel Youngs Co.; formerly known as Co. D; enlisted June 28, 1861, for one year; reorganized May 23, 1862. Captains: Ezekiel Young, Calvin H. Senter (resigned, 1862), William C. Bourn (wounded, 1864)

Co. K, Capt. Stephen M. Dickeys Co.; formerly called Co. A; enlisted June 24, 1861, for one year; reorganized May 6, 1862. Captains: Stephen Mills Dickey (to Major, May 26, 1862), William A. Cooper (resigned, January 25, 1865).