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
Chico Marx his fly until he was seventy." Chico's lifelong gambling addiction compelled him to continue in show business long after his brothers had retired in comfort from their Hollywood income, and in the early 1940s he found himself playing in the same small, cheap halls in which he had begun his career 30 years earlier. The Marx Brothers' penultimate film, "A Night in Casablanca" (1946), was made for Chico's benefit since he had filed for bankruptcy a few years prior. Because of his out-of-control gambling, the brothers finally took the money as he earned it and put him on an allowance,