The second USS Portsmouth was a wooden sloop-of-war in the United States Navy in service during the mid-to-late 19th century. She was designed by Josiah Barker on the lines of a French-built privateer, and built at the Portsmouth Navy Yard, directly across the Piscataqua River from Portsmouth, New Hampshire. She was described as an improvement over built in the same shipyard a year earlier. Portsmouth was launched on 23 October 1843 and commissioned on 10 November 1844, with Commander John Berrien Montgomery in command. Service history Mexican–American War, 1845–1848 Portsmouth had an important role during the Mexican–American War, seizing the port of Yerba Buena (today's San Francisco) from Mexico. She had set sail on 25 January 1845 from Norfolk, Virginia, on a cruise around Cape Horn to join the Pacific Squadron under the command of Commodore John D. Sloat. En route, she made stops in Rio de Janeiro, Valparaiso, Callao, the Sandwich Islands, and Acapulco. Upon arriving off the Departamento de Las Californias coast, with Lieutenant Benjamin F. B. Hunter as her Sailing Master, she was initially engaged in watching the movements of British vessels there to prevent the possibility of Great Britain acquiring the region during any conflict between the U.S. and Mexico. After the declaration of war with Mexico, a detachment of Marines under the command of Second Lieutenant Henry Bulls Watson rowed ashore on 9 July 1846, marched to the pueblo's main plaza, and raised the American flag, thereby seizing the city. Renamed Portsmouth Square, the site is located in modern Chinatown. In the square there is a US Flag flown from a flagpole and a commemorative plaque set by the Daughters of the American Revolution. Portsmouth remained in San Francisco Bay until November 1846, when she was sent to San Diego. During 1847, under the command of Montgomery, she was assigned to blockade Mexico's west coast, arriving with USS Congress and USS Argo at Guaymas on 17 October. After a request to surrender was rejected the ships began a bombardment of the city, lasting an hour. After the town surrendered a garrison was sent ashore and occupied the city. Her duty completed by early 1848, she got underway for the cruise back to the U.S. east coast on the morning of 3 January. West Africa, 1848–1851 Returning to Boston in May 1848 she departed again on 29 August and sailed east to the African coast. There