First built between 1872-1876, Fort Mott was one of three forts constructed to protect the Delaware River (the other two were Fort Delaware on Patch Island and Fort DuPont in Delaware City). The site is now a park and directly adjacent is the Finn's Point National Cemetery, which is listed on the National Register of Historic Places. The forts were were part of a larger post Civil War effort to modernize the country's coastal defenses. Of the original plan of eleven gun emplacements with twenty guns and a mortar battery with 6 emplacements, just two gun emplacements and two magazines in the mortar batteries were built by 1876. In anticipation of the Spanish-American War (April-August, 1898) the federal government initiated another modernization plan beginning in 1885 and by 1902, Fort Mott was greatly expanded and, interestingly, designed to repel a ground attack. Today, visitors can explore the fortifications and walk along an interpretive nature trail.
Troops were stationed here from 1897-1922. Fort Saulsbury, near Millford, Delaware, was built after WWI and made the other three forts obsolete. A caretaking detachment remained until 1943. New Jersey acquired the site in 1947 and opened it to the public as a state park in 1951.