Fort Mansfield Fort Mansfield was a coastal artillery installation located at the end of Napatree Point , a long barrier beach in the village of Watch Hill in Westerly , Rhode Island . History . Fort Mansfield and similar forts stretching from Galveston to Maine can be traced back to a joint Army - Navy Board created in 1883 known as the Gun Foundry Board . Its report a year later warned of the defenseless condition of the USA ' s coasts and recommended a system of fortifications to protect harbors and coastal cities from invasion . In 1885 this Board was replaced by what has become known as the Endicott Board which in 1886 issued formal recommendations for a major coastal defense network . Fort Mansfield was one of numerous coastal artillery installations constructed to guard the eastern entrance to Long Island Sound as part of the coastal defense network for New York City . It was named in honor of Joseph K . Mansfield ( 1803 – 1862 ) who had served as Chief Engineer Of The Army during the Mexican War and was eventually promoted to Inspector General Of The Army . Construction . In 1898 the United States government purchased on Napatree Point , a long , narrow spit of land jutting out from Watch Hill . The fort was located on a bend in the spit beyond which was called Sandy Point . Construction of the fort began the following year . When the fort was first manned in 1901 it was considered a sub - post of Fort Trumbull in New London , Connecticut . But when the fort was fully manned in 1902 its status changed to an independent battery . The fort ’ s main armaments consisted of two Crozier disappearing guns plus several rapid - fire cannon and were divided among three batteries : Wooster , Crawford , and Connell . Fatal flaw . War games held in 1907 proved the fort had a fatal flaw . Any attacking vessel could approach Fort Mansfield from a “ dead angle ” along the Rhode Island coast which its long - range 8 inch cannon , did not cover . The installation could be bombarded with impunity and depending on where an invading party landed , it could assault the fort opposed by nothing better than small - arms fire . A report on the war games stated " . . . I believe I could capture Ft . Mansfield with a fleet of coal barges , equipped with 6 - inch rapid fire guns " . Because of this fatal design flaw , the fort was removed from the list of active coastal artillery posts in 1909 . By 1911 only 18 men were left to man the post . That dropped to six men in 1916 and that small contingent remained until 1926 when the government placed the land up for sale . With one developer proposing nearby land on Sandy Point to be divided up into some 674 plots , the land was purchased by a private syndicate eager to prevent the land from being used for “ cheap little houses ” that might affect the exclusive character of Watch Hill . The sale was finalized in 1928 . Demolition . All the government buildings were demolished during the winter of 1928 – 29 leaving the three concrete gun emplacements behind . Batteries Wooster and Crawford , while overgrown , survive to this day but Battery Connell has succumbed to sea erosion which has pushed the beach back some since the fort was built . What remains of Connell can sometimes be seen at low tide . Cleanup . In August 2009 , a small group of young adults interested in historical preservation began a cleanup project on Fort Mansfield . Finding roots to be the major source of cracks and deterioration , foliage was cut back . The fort ' s decay has slowed because of the lack of the roots ' pressure against the structure . While this project proved beneficial in alleviating some of the stresses upon the fort , efforts from the community must occur to maintain the integrity of the constructions . In 2011 , the Watch Hill Fire Department placed railings along the top edges of the main building to prevent people from enjoying and exploring the fort . They also placed steel covers blocking the steps to prevent tourists from accessing the lower level of the site .