• Type: Casemate Ram 
  (converted from the frigate U.S.S. Merrimack)
• Commission: February 17, 1862
• Cost: $110,000
• Length: 275 feet
• Beam (Width): 38 feet, 6 inches
• Displacement: 3,500 tons
• Draft: 19 1/2 to 22 feet
• Speed: 6 knots
• Crew: 320 officers & men
• Weapons: Two 7-inch rifles, six 9-inch smoothbore guns, two 6-inch 32-pdr rifles  
• Engines: Horozontal, back acting; two cylinders, 72" in diameter, 3' stroke
• Boilers: 4 Martin type boilers; average steam pressure, 18 lbs.
• Commanders: Capt. Franklin Buchanan (Feb-Mar 62), Lt. Catesby ap R. Jones (Mar-Apr 62), Capt. Josiah Tattnall (Apr-May 62).
• Built In: Boston Navy Yard, Mass, Refit Portsmouth, Va.
• Current Disposition: Destroyed to prevent capture near Craney Island VA 11 May 1862. Remains removed in 1870s.

CSS Virginia was built at Boston Navy Yard as the frigate Merrimack, commissioned 20 February 1856, Capt. G. J. Pendergrast, USN, in command.

Departing Boston she cruised in West Indian and European waters in 1856- 57. Following brief repairs she sailed in October 1857 as flagship of the Pacific Squadron, cruising the Pacific coasts of South and Central America until November 1859. Returning east she decommissioned at Norfolk 16 February 1860. On 20 April 1861 retiring Union forces burned Merrimack to the water line and sank her to preclude capture.

USS Merrimack becomes CSS Virginia

When the Commonwealth of Virginia seceded from the Union in 1861, one of the important federal military bases threatened was Gosport Shipyard (now Norfolk Naval Shipyard) in Portsmouth, Virginia. Accordingly, the order was sent to destroy the base rather than allow it to fall into Confederate hands. Unfortunately for the Union, these orders were bungled. The steam frigate USS Merrimack sank before it completely burned. When the Confederates entered the yard, they raised the Merrimack and decided to use the engines and hull to build an ironclad ram.

This new ship was named Virginia. It had an iron deck and casement, four inches thick. It mounted ten cannons, one in front and rear and four on each side. Further, the designers of the Virginia had heard of plans by the North to build an ironclad. Figuring that cannons would be unable to harm such a ship, and to conserve gunpowder, they equipped the Virginia with a ram. The Merrimack's engines, now part of the Virginia, had not been in good working order, and the salty Elizabeth River water did not help it very much. The addition of a number of tons of iron did not improve the situation.