Initially constructed to have a garrison of 800 troops, the fort never had that many and mainly had the role as a military deterrent along the border. Many of the Third System forts by design were never fully garrisoned, ultimately they were to be ready for action as needed.
Contrary to local legend, however,the fort never fired a shot in anger, but this does not mean it didn't have some of its guns mounted.
According to War Department records in 1886, when Fort Montgomery was most heavily armed, it mounted 74 guns of its 125 capacity, including 8 and 10-inch Rodmans, some of the heaviest caliber cannons in the U.S. arsenal.
Most of these cannons were mounted facing Canada. Although never mounted, two huge 15-inch Rodmans were on site on the parade ground for years. They were to be mounted on top of the wall.
In 1880, commander of the U.S. Army, William Tecumseh Sherman, toured the fortification and was so im pressed that he wanted the garrison at nearby Plattsburgh Barracks to be stationed there, but public outcry kept that from happening.
--Brock-Perry