USS Constellation is a sloop-of-war, the last sail-only warship designed and built by the United States Navy. She was built at the Gosport Shipyard between 1853 and 1855. She was named for the earlier frigate of the same name that had been broken up in 1853. The sloop's primary armament was 8-inch (203 mm) shell-firing guns and four 32-pounder long guns, though she carried other guns as well, including two Parrott rifle chase guns. Constellation's career as a front-line unit was relatively short; after entering service in 1855, she served with the Mediterranean Squadron until 1858, and in 1859, she was assigned as the flagship of the Africa Squadron, where she served with the African Slave Trade Patrol. During the American Civil War (1861–1865), the ship returned to the Mediterranean to patrol for Confederate vessels. In late 1864, she returned to the United States to be decommissioned, as most of her crews' enlistments had expired. She spent the rest of the war out of service.

Constellation was recommissioned in 1871 for use as a training ship, being used for shooting practice and training cruises for midshipmen. She filled this role for twenty-two years, and during this period, she saw a number of other activities, including transporting exhibits for the 1878 Exposition Universelle in Paris and carrying food to Ireland during the 1879 Irish famine. She was reduced to a stationary training hulk in late 1893, being moored in Newport for the next twenty years. During this period, the mistaken belief that the two Constellations were one and the same arose, and she was presented as such in 1914 during the centennial of the writing of "The Star-Spangled Banner", the national anthem of the United States. Briefly renamed Old Constellation in 1917 to free the name for a new battlecruiser of the Lexington class, she reverted to her original name when the battlecruiser was scrapped in 1925. Constellation was recommissioned in 1940 as part of the build-up in anticipation of the United States' entry into World War II, during which she served as the port flagship of the commander of the Atlantic Fleet.

Proposals to restore the vessel as a museum ship had been submitted already in the 1930s, but work began in earnest after World War II. Shortages of funds prevented her transfer to the city of Baltimore, Maryland until 1955. Operating under the mistaken belief that she was the original Constellation, the organization responsible for the ship modified her to match the earlier vessel's appearance during a refit in the late 1950s and early 1960s. During this period, a controversy arose over the vessel's identity that lasted into the 1990s, when new research definitively proved that the Constellation launched in 1797 and the 1854-launched vessel were distinct ships. Periodic repairs have been carried out since the mid-1990s to repair rotted wood. Constellation remains open to the public as part of the Historic Ships in Baltimore in the city's Inner Harbor, having been designated a National Historic Landmark.

From 1816 to the 1830s, the Navy accumulated extensive stocks of live oak timbers for use in new warship construction under the provisions of the Act for the Gradual Increase of the Navy of the United States, passed in 1816. In the early 1850s, the Navy decided to build a new sail-powered ship using these existing stockpiles, calling for a sloop-of-war that would be fast, with a long endurance, and sufficiently armed to be capable of engaging other warships of her type. This would produce a capable warship while keeping costs low since the material used was already on hand and an expensive steam engine would not be required. Chief Constructor John Lenthall prepared the design, along with Edward Delano, the constructor of the Gosport Shipyard. In June 1853, Lenthall completed the hull half model, which was necessary to scale up the design and to prepare the necessary hull timbers. During this period, the new vessel's namesake, Constellation, was in the process of being broken up a short distance away in the Gosport yard.

Beginning in May 1853, work on assembling the timbers commenced, as the shipyard workers prepared to start construction of the new sloop-of-war. The vessel's keel was laid down on 25 June 1853, using material from the oak stockpile; her sternpost was erected on 27 August, and her stem followed a couple of weeks later. She was launched on 26 August 1854 at 11:45. Fitting-out work then commenced, which included the installation of her masts, rigging, and armament.

Constellation is 181 feet (55 m) long at the waterline and 199 feet (61 m) long overall. She has a beam of 41 feet (12 m) at the waterline, and is 43 feet (13 m) across at her widest point. Her maximum draft is 21 feet (6.4 m) at a full load displacement of 1,400 long tons (1,422 t). The ship's crew numbered 21 officers and 265 enlisted men.

In her original configuration, Constellation was armed with a battery of sixteen 8-inch (203 mm) shell-firing guns and four 32-pounder guns mounted on her gun deck in the main battery. On her spar deck, she carried a pair of chase guns; a 30-pounder Parrott rifle was placed in the bow and a 20-pounder Parrott rifle was placed in the stern. She also carried three 12-pounder boat howitzers.

Constellation was commissioned on 28 July 1855, under the command of Captain Charles H. Bell. She immediately departed for a tour with the Mediterranean Squadron that lasted three years. During this period, she stopped in Málaga, Spain in July 1856 to protect American nationals in the area during a period of civil unrest. Later that year, she came to the aid of a barque in the Sea of Marmara; the ship received an official thanks from the Emperor of Austria. On 17 April 1858, she left the Mediterranean Squadron for a short patrol in the Caribbean Sea to protect American shipping in the region. On 5 June she returned to the New York Navy Yard before proceeding to Boston, where she was decommissioned on 13 August.