Naval History and Heritage Command

The U.S. Naval Armed Guard crew on board SS Mongolia engages and damages a German U-boat, the first engagement against the enemy after declaration of war on April 6.

The first German submarine brought to the United States after World War I arrives at New York. During World War I, U 111 sank three Allied merchant vessels that included the British steamer Boscastle on April 7, 1918. The submarine surrendered later that year.

USS Buckley (DE 51) and USS Reuben James (DE 153) sink the German submarine U-879 southeast of Halifax, Nova Scotia.

USS Albany (CA 123) and USS William Wood (DD 715) begin providing disaster relief to citizens of Volos, Greece, following a catastrophic earthquake.

The Grumman A2F-1 Intruder makes its first flight. The Intruder receives the designation of A-6A in 1962, and upon entering service in 1963, becomes the U.S. Navy and Marine Corps principle all weather/night attack aircraft.

USS The Sullivans (DDG 68) is commissioned at Staten Island, N.Y. The Arleigh Burke-class guided-missile destroyer is the second Navy ship named after the five Sullivan brothers who died when USS Juneau (CL 52) was sunk shortly after the Battle of Guadalcanal Nov. 13, 1942.

The Cyclone-class patrol coastal ship USS Zephyr (PC 8), its embarked U.S. Coast Guard Law Enforcement Detachment (LEDET) personnel and coalition forces pursue and board a small fishing vessel, called a panga, and interdict 750 kilograms of cocaine with a total street value of $22.5 million.