During the Civil War the fort had numerous cannons mounted on the ramparts and inside the casemates to protect the harbor from enemy attack. In the late 1800s, the Endicott Board recommended new coastal defenses about the time that concrete became a viable material for constructing gun batteries. Large masonry forts were no longer needed to protect cities since concrete gun emplacements could be situated just about anywhere. Fort Warren was upgraded in the 1890s to include several of these new concrete gun fortifications which were called "Endicott Period" modifications.
Fort Warren sometime after the Civil War ended. Battery Jack Adams was later constructed in the foreground area.
Battery Jack Adams was one of the first concrete gun batteries ever installed in the country.
It was never used because of the poor quality concrete and later disarmed in 1914.
One of Battery Plunkett's two rapid fire gun mounts. It was disarmed about 1925.
Battery Lowell had three rapid fire guns installed. It was disarmed about 1920.
Battery Stevenson mounted two 12-inch disappearing rifles. Battery #1 is test firing about 1910. When the huge guns were fired, the carriages recoiled and the guns "disappeared" behind the massive concrete walls, ready for reloading.
Battery Stevenson #2 emplacement. The battery's 12-inch guns were most powerful artillery ever installed at the fort. They had a range of about 8 miles. This battery was disarmed in 1944 as the war shifted to offensive in Europe.
Battery Bartlett had four 10-inch disappearing rifles. It was constructed outside of the fort's protective walls.
Emplacement #2 in Battery Bartlett. Gun batteries were numbered from right to left. In 1976
emplacement #4 was demolished in order to repair the seawall in front of it which had collapsed.