Virginia's Johnson Heavy Artillery

Organized in September 1861
Reorganized in 1862 under the same captain, the unit was stationed for some time at Drewry's Bluff attached to F. W. Smith's Battalion.
During February 1864, it was serving as infantry and in May belonged to Ransom's Brigade in the Richmond and Petersburg lines.
On April 9, 1865, it surrendered with the Army of Northern Virginia.
Captain Branch J. Epes was in command.
AKA - Epes' Company, Virginia Heavy Artillery

Roster under alternate company name of Epes' Company Heavy Artillery:

Name listing (Ranger95)
Soldiers and Sailors Database (National Park Service) - includes details along with names