The aircraft was named Phantom II on July 3, 1959, during a ceremony held at the McDonnell plant in St. Louis, Mo., to celebrate the company's 20th anniversary. It remained in production until the company's 40th anniversary. By then, the numeral "II" had been discontinued; it had become the only Phantom.The McDonnell two-place, twinjet, all-weather F-4 Phantom II, with top speeds more than twice that of sound, was one of the most versatile fighters ever built. It served in the first line of more Western air forces than any other jet. Just 31 months after its first flight, the F-4 was the U.S. Navy's fastest, highest flying and longest range fighter. It first flew May 27, 1958, and entered service in 1961.