On July 21, 1921, Brig. Gen. William "Billy" Mitchell circled high above the rough surface of the Chesapeake Bay, exultant witness to an event he had orchestrated and produced. Shortly after noon, the mortally wounded, former- German battleship Ostfriesland began to roll, turning completely over while air escaping from the huge hull gave sounds that some present interpreted as the sighs of a great beast dying. By one o'clock it was over, and Ostfriesland had slipped below the surface. It was not the sinking that was unique, however. Modern battleships had sunk before. They had been lost in storms and split their hulls on reefs and rocks. They had been hit by torpedoes, crushed by shell fire, and even sunk by mines and scuttling charges. But no battleship had ever gone to the bottom as the direct result of aerial bombs dropped from the fragile airplane, a new invention then barely eighteen years old. Disbelieving observers aboard the nearby U.S.S. Henderson were shocked, appalled, and dismayed as the Ostfriesland disappeared. Among the naval officers were some with tears in their eyes. But for the outspoken, flamboyant Billy Mitchell it was fulfillment and vindication. He had prophesied that aircraft could sink battleships; had fought for the trials that had just taken place; and had selected, organized, and trained the airmen who had accomplished their mission. Sinking the Ostfriesland was in many ways the summit of his military career, and Billy was not about to let anyone ignore his victory. Command pennant streaming from his aircraft, Mitchell paraded past the Henderson waving his wings, rubbing salt into a deep Navy wound.