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 Ramon Blanco y Erenas, the top military commander in Cuba, ordered it to sortie from the harbor along the coast westward to Cienfuegos. In Cervera's eyes, the escape from the bay seemed nearly impossible. He strongly considered fleeing under protection of night, but opted to sail by day instead to ensure the safe navigation of his ships through Santiago's narrow channel. On Sunday July 3, 1898, Cervera, aboard his flagship "Infanta Maria Teresa", led the Spanish fleet out of the safety of Santiago harbor at seven minute intervals. The primary elements of the American forces in Cuban waters were initially