42°8′14″N 80°5′15″W / 42.13722°N 80.08750°W / 42.13722; -80.08750

USS Niagara, commonly called the U.S. Brig Niagara or the Flagship Niagara, is a wooden-hulled snow-brig^[b] that served as the relief flagship for Oliver Hazard Perry in the Battle of Lake Erie during the War of 1812. As the ship is certified for sail training by the United States Coast Guard, she is also designated SSV Niagara. Niagara is usually docked behind the Erie Maritime Museum in downtown Erie in the U.S. state of Pennsylvania as an outdoor exhibit for the museum. She also often travels the Great Lakes during the summer, serving as an ambassador of Pennsylvania when not docked. It was listed on the National Register of Historic Places in 1973 and was designated the official state ship of Pennsylvania by the Pennsylvania General Assembly in 1988.

Niagara was constructed from 1812 to 1813 to protect the vulnerable American coastline on Lake Erie from the British and played a pivotal role in the battle for the lake. Along with most warships that served in the war, Niagara was sunk for preservation on Presque Isle in 1820. Raised in 1913, it was rebuilt for the centennial of the Battle of Lake Erie. After deteriorating, the restoration of Niagara was started again in the 1930s, but was hampered by the lack of funds caused by the Great Depression and remained uncompleted until 1963. A more extensive restoration was carried out in 1988 in which much of the original ship was largely destroyed. The incorporation of new materials and modern equipment makes it ambiguous as to whether it is or is not a replica.

In 1907, President Theodore Roosevelt issued an executive order standardizing the prefix of all vessels of the United States Navy to be "USS". Prior to this, ship prefixes were used "haphazardly", but ships' names were often preceded by the abbreviation "US" and the type of vessel. A survey of documents contained in the National Archives and Records Administration that were sent to and from the Department of the Navy in that era found a number of inconsistencies. Of 55 correspondences that mentioned Niagara, 43.6 percent used the term "US Sloop Niagara", 32.7 percent used "US Brig Niagara" and 23.6 percent had "USS Niagara".

Because of its historical role as the flagship of Oliver Hazard Perry during the Battle of Lake Erie, the ship is commonly referred to as the Flagship Niagara. Niagara also carries the name of "SSV Niagara" due to its designation by the United States Coast Guard as a Sailing School Vessel.^[a]

In the beginning of September 1812, Daniel Dobbins, a merchant on the Great Lakes, arrived in Washington, D.C., to warn the United States government of the vulnerability of the Lake Erie coastline to a British attack. Dobbins had been captured by the British after a surprise attack at Fort Mackinac in Michigan, but was able to negotiate his release. Dobbins was briefly detained again by the British in Detroit after the city was captured. After several days of discussions with President James Madison and Secretary of the Navy Paul Hamilton, Dobbins convinced them that the safest place to build a fleet was in the sheltered bay formed by Presque Isle at Erie, Pennsylvania. On 15 September, Hamilton authorized Dobbins to construct four gunboats. Hamilton also granted $2,000 to be used for the construction and appointed Dobbins, a civilian, to the rank of sailing master in the United States Navy. On 31 December, Captain Isaac Chauncey, the commander of naval forces on Lake Ontario, arrived in Erie for a day, made some alterations to Dobbins' ship design and authorized him to build, additionally, two brigs. Oliver Hazard Perry was named chief naval officer in February 1813 and was given orders to report to Erie from Newport, Rhode Island. Perry arrived in Erie on 26 March, after being held up in Sackets Harbor, New York for two weeks by Chauncey in case of a possible attack by the British.

The construction of the fleet was largely supervised by Noah Brown, a shipwright brought in from New York City. The keels of two brigs were each constructed out of a single 14-by-18-inch (360 mm × 460 mm) black oak log. Due to a lack of iron, the timbers that made up the hulls were joined using wooden pins called treenails. In place of the oakum and pitch normally used to caulk ships, lead was used. The timbers used in the brigs were still green, as the builders did not have the luxury of time to allow the wood to dry properly. A total of 65 cannons were shipped to Erie to arm the fleet; Hamilton approved the production of 37 cannons by a foundry in Washington, D.C., and the rest were moved from Sackets Harbor. Tigress and Porcupine were launched in April 1813, Scorpion in May, and the brig Lawrence on 25 June. Niagara was launched on 4 July along with Ariel.

One of the strategic advantages of building a fleet in Erie was that the bay formed by Presque Isle was cut off from the Lake Erie by a sandbar, which prevented British warships from being able to enter the bay. The brigs Niagara and Lawrence both had a draft of 9 feet (2.7 m), which was too deep to cross the sandbar. On 4 August, Niagara was pulled onto the sandbar using its anchor in a technique called kedging and was lightened by removing its cannons and ballast. A pair of 90-by-40-foot (27 by 12 m) barges, called "camels", were placed on either side of the ship. The camels were sunk and secured to Niagara. The water was pumped out of the camel, lifting the ship. By the following day, Niagara was safely over the sandbar and was rearmed; Lawrence was floated over the sandbar a couple of days before Niagara. During the construction, the area was usually under daily surveillance by the British. On the day Lawrence crossed the sandbar, a pair of British warships, Queen Charlotte and Lady Prevost, observed for an hour but failed to notice Perry's actions.