Marx Brothers made a guest appearance to introduce the "Tonight Show's" new host, Johnny Carson. Around 1960, the acclaimed director Billy Wilder considered writing and directing a new Marx Brothers film. Tentatively titled "A Day at the U.N.", it was to be a comedy of international intrigue set around the United Nations building in New York. Wilder had discussions with Groucho and Gummo, but the project was put on hold because of Harpo's ill-health and abandoned when Chico died in 1961. He was 74. Three years later, on September 28, 1964, Harpo died at the age of 75 of a heart attack
Marx Brothers biopic entitled "The Life and Times of the Marx Brothers". In addition to being a non-fiction biography of the Marxes, the film would have featured the brothers reenacting much of their previously unfilmed material from both their vaudeville and Broadway eras. The film, had it been made, would have been the first performance by the Brothers as a quartet since 1933. The five brothers made only one television appearance together, in 1957, on an early incarnation of "The Tonight Show" called "Tonight! America After Dark", hosted by Jack Lescoulie. Five years later (October 1, 1962) after Jack Paar's tenure, Groucho