USS Merrimack; Engraving by L.H. Bradford & Co., after a drawing by G.G. Pook.
|Career (US)|| 50px<tr valign=top><td>Name:</td><td>
April 6, 1854</td></tr><tr valign=top><td>Launched:</td><td>
June 15, 1855</td></tr><tr valign=top><td>Commissioned:</td><td>
February 20, 1856</td></tr><tr valign=top><td>Decommissioned:</td><td>
February 16, 1860</td></tr><tr valign=top><td>Fate:</td><td>
Burned and sunk in dock, April 20, 1861
| General characteristics
3,200 tons</td></tr><tr valign=top><td>Length:</td><td>
Template:Ft to m/ID</td></tr><tr valign=top><td>Beam:</td><td>
Template:Ft to m/ID</td></tr><tr valign=top><td>Draft:</td><td>
Template:Ft to m/ID</td></tr><tr valign=top><td>Propulsion:</td><td>
sail, steam engine</td></tr><tr valign=top><td>Speed:</td><td>
12 knots</td></tr><tr valign=top><td>Armament:</td><td>
14 × 8-inch guns,
USS Merrimack (sometimes spelled without the "k") was a frigate of the United States Navy, best known as the hulk upon which CSS Virginia was built during the American Civil War and then took part in the Battle of Hampton Roads (often called "the Battle of the Monitor and the Merrimack").
Merrimack was launched by the Boston Navy Yard June 15, 1855; sponsored by Miss Mary E. Simmons; and commissioned February 20, 1856, Captain Garrett J. Pendergrast in command. She was the second ship of the Navy to be named for the Merrimack River, which is formed by the junction of the Pemigewasset and Winnipesaukee Rivers at Franklin, New Hampshire. The Merrimack flows south across New Hampshire, and then eastward across northeastern Massachusetts before emptying in the Atlantic at Newburyport, Massachusetts.
Shakedown took the new screw frigate to the Caribbean and to western Europe. Merrimack visited Southampton, Brest, Lisbon, and Toulon before returning to Boston and decommissioning April 22, 1857 for repairs. Recommissioning September 1, 1857, Merrimack got underway from Boston Harbor October 17 as flagship for the Pacific Squadron. She rounded Cape Horn and cruised the Pacific coast of South and Central America until heading for home November 14, 1859. Upon returning to Norfolk, she decommissioned February 16, 1860.
Merrimack was still in ordinary during the crisis preceding Lincoln's inauguration. Soon after becoming Secretary of the Navy, Gideon Welles took action to prepare the frigate for sea, planning to move her to Philadelphia. The day before the firing on Fort Sumter, Welles directed that "great vigilance be exercised in guarding and protecting"; Norfolk Navy Yard and her ships. On the afternoon of April 17, the day Virginia seceded, Engineer in Chief B. F. Isherwood managed to get the frigate's engines lit off; but the previous night secessionists had sunk lightboats in the channel between Craney Island and Sewell's Point, blocking Merrimack. On the April 20, before evacuating the Navy Yard, the U.S. Navy burned Merrimack to the waterline and sank her to preclude capture.
The Confederacy, in desperate need of ships, raised Merrimack and rebuilt her as an ironclad ram, according to a design prepared by Lt. J. M. Brooke, CSN. Commissioned as CSS Virginia February 17, 1862, the ironclad was the hope of the Confederacy to destroy the wooden ships in Hampton Roads, and to end the Union blockade which had already seriously impeded the Confederate war effort.