Seavey's Island side of Seavey's Island at the former site of Camp Long, a stockade named for Secretary of the Navy John Long, where 1,612 prisoners of war from the Battle of Santiago de Cuba were confined from July 11 to mid-September 1898 during the Spanish–American War. Camp Heywood, a Marine camp named after Colonel Charles Heywood, was located just north of the naval prison. It was occupied after the 1st Battalion's return from Cuba in late August until September 21, 1898. According to the National Trust for Historic Preservation, the Portsmouth Naval Shipyard has 62 buildings listed on the National Register
Battle of Santiago de Cuba (1748) and the 16-gun, 100-man sloops "Merlin" and "Weazel". He had initially intended to take his squadron and attack Santiago de Cuba, but contrary winds led to him deciding instead to attack Fort Saint Louis de Sud. He arrived on 8 March 1748, and after subjecting the fort to a heavy bombardment forced its surrender. Attacks on Petit-Goâve and Cap-Français, however, had to be postponed due to lack of troops. It was therefore decided to proceed with the attack upon Santiago. The afternoon of 28 March, having been joined by "HMS Lenox" and the frigates "Vainqueur", "Vulture", and the tender "Sharp",