Idelwild International Airport, as JFK used to be known, was opened on July 1, 1948 under the administration of New York City Mayor, Fiorello H. La Guardia. Covering over two thousand hectares, it became the largest airport in the United States. Its design was considered particularly unusual at the time since terminals and parking space were arranged in the middle of the airport. Airlines were also encouraged to build their own terminals, a unique concept at the time. The first jet service offered by an American airline, a Pan American Airways Boing 707, flew to London on October 26, 1958 in seven hours and twenty-seven minutes. In 1963 the airport was renamed John F. Kennedy Airport. During the 1970s and 1980s, JFK became the busiest cargo airport in the world, serving more than fifty-seven cargo airlines a year.