Camillus made the first USN fighting knife. The knife had a heavy, threaded butt and because of minor design flaws was promptly returned to the factory. Camillus redesigned the knife, replacing the threaded nut with a steel pin. The new design was deemed acceptable, hence the designation USN Fighting Knife, Mark 2.

In 1944, the US Navy put through a change order to have the markings moved from the blade to the cross guard, so this knife was produced after that change.