American Civil War: USS Monitor

USS Monitor
US Naval History & Heritage Command

One of the first ironclads constructed for the US Navy, the origins of USS Monitor began with changes in naval ordnance during the 1820s. Early in that decade, French artillery officer Henri-Joseph Paixhans developed a mechanism that allowed for shells to be fired with flat trajectory, high-powered naval guns. Trials using the old ship-of-the-line Pacificateur (80 guns) in 1824 showed that exploding shells could inflict significant damage on traditional wooden hulls. Refined over the next decade, shell-firing guns based on Paixhans' design were common in the world's leading navies by the 1840s.

Rise of the Ironclad

Recognizing wooden ships' vulnerability to shells, Americans Robert L. and Edwin A. Stevens began the design of an armored floating battery in 1844. Forced to re-evaluate the design due to rapid advances in shell technology, the project came to a halt a year later when Robert Stevens fell ill. Though resurrected in 1854, the Stevens' vessel never came to fruition. During this same period, the French successfully experimented with armored floating batteries during the Crimean War (1853-1856). Based on these results, the French Navy launched the world's first ocean-going ironclad, La Gloire, in 1859. This was followed by the Royal Navy's HMS Warrior (40) a year later.

Union Ironclads

With the start of the Civil War, the US Navy convened an Ironclad Board in August 1861 to assess potential designs for armored warships. Calling for proposals for "iron-clad steam vessels of war", the board sought vessels capable of operating in the shallow waters along the American coast. The board was further spurred to action due to reports that the Confederacy was seeking to convert the captured remains of USS Merrimack (40) into an ironclad. The board ultimately selected three designs to be constructed: USS Galena (6), USS Monitor (2), and USS New Ironsides (18)

Monitor was designed by Swedish-born inventor John Ericsson who had previously had a falling out with the Navy in the wake of the 1844 USS Princeton disaster which had killed six people including Secretary of State Abel P. Upshur and Secretary of the Navy Thomas W. Gilmer. Though he had not intended to submit a design, Ericsson became involved when Cornelius S. Bushnell consulted him regarding the Galena project. In the course of the meetings, Ericsson showed Bushnell his own concept for an ironclad and was encouraged to submit his revolutionary design.


Consisting of a revolving turret mounted on a low armored deck, the design was likened to a "cheese box on a raft." Possessing a low freeboard, only the ship's turret, stacks, and small armored pilot house projected above the hull. This almost non-existent profile made the ship very difficult to hit, though it also meant that it performed badly on the open sea and was prone to swamping. Highly impressed by Ericsson's innovative design, Bushnell traveled to Washington and convinced the Navy Department to authorize its construction. The contract for the ship was given to Ericsson and work began in New York.


Subcontracting the construction of the hull to Continental Iron Works in Brooklyn, Ericsson ordered the ship's engines from Delamater & Co. and the turret from Novelty Iron Works, both of New York City. Working at a frenetic pace, Monitor was ready for launch within 100 days of being laid down. Entering the water on January 30, 1862, workers began finishing and fitting out the ship's interior spaces. On February 25 work was completed and Monitor commissioned with Lieutenant John L. Worden in command. Sailing from New York two days later, the ship was forced to return after its steering gear failed.

USS Monitor - General

  • Nation: United States
  • Builder: Continental Iron Works, Brooklyn, NY
  • Laid Down: October 1861
  • Launched: January 30, 1862
  • Commissioned: February 25, 1862

Fate: Lost at sea, December 31, 1862


  • Type: Monitor-class ironclad
  • Displacement: 987 tons
  • Length: 172 ft.
  • Beam: 41 ft. 6 in.
  • Draft: 10 ft. 6 in.
  • Complement: 59
  • Speed: 8 knots


  • 2 x XI-inch Dahlgren smoothbores

Operational History

Following repairs, Monitor departed New York on March 6, this time under tow, with orders to proceed to Hampton Roads. On March 8, the newly completed Confederate ironclad CSS Virginia steamed down the Elizabeth River and struck at the Union squadron at Hampton Roads. Unable to pierce Virginia's armor, the wooden Union ships were helpless and the Confederate succeeded in sinking the sloop of war USS Cumberland and frigate USS Congress. As darkness fell, Virginia withdrew with the intention of returning the next day to finish off the remaining Union ships. That night Monitor arrived and took up a defensive position.

Returning the next morning, Virginia encountered Monitor as it approached USS Minnesota. Opening fire, the two ships began the world's first battle between ironclad warships. Pounding each other for over four hours, neither was able to inflict significant damage on the other. Though Monitor's heavier guns were able to crack Virginia's armor, the Confederates scored a hit on their adversary's pilot house temporarily blinding Worden. Unable to defeat Monitor, Virginia withdrew leaving Hampton Roads in Union hands. For the rest of the spring, Monitor remained, guarding against another attack by Virginia.

During this time, Virginia attempted to engage Monitor on several occasions but was refused as Monitor was under presidential orders to avoid battle unless absolutely required. This was due to President Abraham Lincoln's fear that the ship would be lost allowing Virginia to take control of the Chesapeake Bay. On May 11, after Union troops captured Norfolk, the Confederates burned Virginia. Its nemesis removed, Monitor began participating in regular operations, including reconnaissance of the James River to Drury's Bluff on May 15.

After supporting Major General George McClellan's Peninsula Campaign in the summer, Monitor participated in the Union blockade at Hampton Roads that fall. In December, the ship received orders to proceed south to aid in operations against Wilmington, NC. Departing under tow by USS Rhode Island, Monitor cleared the Virginia Capes on December 29. Two nights later, it began to take water as it encountered a storm and high waves off Cape Hatteras. Foundering, Monitor sank along with sixteen of its crew. Though in service for less than a year, it profoundly influenced warship design and several similar ships were built for the Union Navy.

In 1973, the wreck was discovered sixteen miles southeast of Cape Hatteras. Two years later it was designated a national marine sanctuary. At this time, some artifacts, such as the ship's propeller, were removed from the wreck. In 2001, recovery efforts began to salvage the ship's steam engine. The next year, Monitor's innovative turret was raised. These have all been taken to the Mariner's Museum in Newport News, VA for preservation and display.


mla apa chicago
Your Citation
Hickman, Kennedy. "American Civil War: USS Monitor." ThoughtCo, Aug. 26, 2020, Hickman, Kennedy. (2020, August 26). American Civil War: USS Monitor. Retrieved from Hickman, Kennedy. "American Civil War: USS Monitor." ThoughtCo. (accessed March 21, 2023).