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 Cream" sketch. In a 1969 interview with Dick Cavett, Groucho said that the two movies made with Thalberg were the best that they ever produced. Despite the Thalberg films' success, the brothers left MGM in 1937; Thalberg had died suddenly on September 14, 1936, two weeks after filming began on "A Day at the Races", leaving the Marxes without an advocate at the studio. After a short experience at RKO ("Room Service", 1938), the Marx Brothers returned to MGM and made three more films: "At the Circus" (1939), "Go West" (1940) and "The Big Store" (1941). Prior to the release