As WWII raged, supply convoys from the United States and Canada faced off with the German U-boat "wolfpacks" throughout the Atlantic Ocean. Although the Wolfpacks nearly crippled the allied war effort early in 1941 and 1942, eventually the Allies were able to turn the tide, culminating in the devastation inflicted inflicted on the German submarine squadrons in 1943. May 1943 became known to the Germans as "Black May." Today's object was captured from a German submarine by American sailors one year later in a daring boarding of a sinking u-boat.