Today in history: On April 30, 1975, the Vietnam War ended as the South Vietnamese capital of Saigon fell to Communist forces. Also on this date: In 1789, George Washington took the oath of office at Federal Hall in New York as the first president of the United States. In 1803, the United States completed its purchase of the 828,000 square mile (2,140,000 square km) Louisiana Territory from France for 60 million francs, the equivalent of about $15 million; the acquisition roughly doubled the