The 76mm L/50 artillery was the first U.S. Navy anti-air gun. It was ordered in 1914 for the new Mississippi class battleships, and was fitted to contemporary destroyers, destroyer-leaders and the light cruisers of the Omaha class. It was constructed from already available surface-fire artillery, and was immensely successful.

    When World War II broke out, it had already been discarded in favor of the 127mm L/25 in most ships that had carried it, but the 1940 King Board, sdiscussing anti-air warfare, proposed the immediate installation of this gun in many ships in lieu of or together with the 28mm (1'1") guns.

    76mm guns of various types, all semi-automatic and using fixed ammunition, were used on destroyer escorts, on APD conversions of existing flush-deck destroyers, on merchant ships and troop transports, on old battleships, and lastly, on fleet submarines. It displayed an excellent combat record. The arctic convoys, for example, often faced with terrifying German air attacks, regarded the gun as their most effective defense. Alas, it had many problems, the most severe of which, with regard to its AA role, was its lack of a power-drive, which precluded director control since data transmission could not be effected automatically, and second, only in a small degree less important, it did not have a quick enough rate of fire. However, it was the smallest weapon capable of employing the famous VT-fuze, the proximity fuze, which made it a rather effective weapon even in 1945.

    With the Kamikaze crisis and the dire need of effective anti-air weapons, a powered version of the gun with high rate of fire (40 - 50 rounds per minute) was designed, but didn't see service during the war, and neither did a L/70 version.