Fort Massachusetts, Civil War fort on Ship Island, Mississippi, US.

Fort Massachusetts is a brick fort on the north shore of West Ship Island, Mississippi. Its plan is a rounded half-circle closed at the rear by a defensive barracks, with guns mounted both in the casemates and on the roof. The walls show distinct bands of brick from Louisiana and New England.

Construction of Fort Massachusetts began in June 1859 under the Army Corps of Engineers, using bricks from Louisiana; the outer wall stood 6 to 8 feet above the sand by early 1861. Mississippi militia seized the unfinished fort in January 1861, and on 9 July 1861 the USS Massachusetts exchanged twenty minutes of cannon fire with Confederate guns, the only engagement at the site. Union forces took the island and used it to stage the 1862 capture of New Orleans; work resumed in 1862 and ended in autumn 1866.

The fort shows how 19th-century builders mastered brick construction to protect their coast from threats. You can see the skilled work that went into creating this massive defensive structure.

Access to the fort is arranged through guided tours offered on multiple days each week. It is best to contact ahead to confirm current hours and tour availability before planning your visit.

The fort was never officially named; wartime records called it simply the "Fort on Ship Island." The name Massachusetts, first used during the Civil War, probably honors the USS Massachusetts, which exchanged fire with the fort's guns on 9 July 1861.