At the beginning of World War I, the only effective submarine deterrents were large torpedo destroyers. The ships were both incredibly expensive and time-consuming to build. To quickly increase the number of vessels capable of engaging in combat with U-boats, the Navy Department commissioned the construction of over 400 subchasers in 18 months. One hundred seventy vessels were sent overseas to serve in Queenstown, Brest, Gibraltar, and Corfu. | Date: 1918 | Source: Wikimedia Commons, U.S. National ArchivesDownload Original File
