Fort Warren was the headquarters of the Coast Defenses of Boston in World War I. In 1917–1918 the four 10-inch guns of Battery Bartlett were removed for potential service as railway artillery on the Western Front. Contrary to some references, although some 10-inch guns were shipped to France to be mounted as railway guns, none appear to have been used in action in World War I. Different 10-inch M1888 guns, including two from Battery Reilly at Fort Adams in Rhode Island and two from storage, replaced these weapons in 1919.