Fort DuPont State Park is a Delaware state park located in Delaware City, Delaware. Fort DuPont itself, named after Rear Admiral Samuel Francis duPont, was used as a military base from the Civil War through World War II, and was part of a three fort defense system, with Fort Delaware and Fort Mott with the purpose of protecting the Delaware River and the city of Philadelphia from naval attacks. Fort DuPont State Park is situated along the Delaware River and Chesapeake and Delaware Canal.