Fort Mott, located in Pennsville, Salem County, New Jersey, was part of a three-fort defense system designed for the Delaware River during the postbellum and Endicott program modernization periods following the American Civil War and in the 1890s. The other two forts in the system were Fort Delaware on Pea Patch Island and Fort DuPont in Delaware City, Delaware.
Original plans for Fort Mott specified eleven gun emplacements with twenty guns and a mortar battery with six emplacements for Rodman smoothbore guns. Construction was started in 1872, however, only two of the gun emplacements and two magazines in the mortar battery were completed by 1876 when all work stopped. The Board of Fortifications, often called the Endicott Board, recommended a comprehensive program of new fortifications in 1885. A new Fort Mott was one of the results, and it was completed by 1902. Unusually for US forts of its era, it was designed to resist a land attack.
A general War Department Order #72, issued on December 16, 1897, designated the new fort as Fort Mott, in honor of Major General Gershom Mott, of Trenton. Gershom Mott had served with distinction as Second Lieutenant in the Tenth Infantry in the Mexican-American War, as Lieutenant-Colonel in the 5th New Jersey Volunteer Infantry, as Colonel and commander of the 6th New Jersey Volunteer Infantry before he was promoted to first Brigadier General. He was wounded four times, resigned from the Army in 1866 and died on November 29, 1884.