[7] Backus was acting on radio as early as 1940,[4] playing the role of millionaire aviator Dexter Hayes on Society Girl on CBS.

[8] He had an extensive career and worked steadily in Hollywood over five decades, often portraying characters with an "upper-crust", New England-like air, much like his best-known role, Thurston Howell III on Gilligan's Island.

Years later, when Backus was a frequent talk show guest, he would recount the time Marilyn Monroe urgently beckoned him into her dressing room.

He came home one night during the filming and told me that Miss Monroe in her most seductive breathy voice asked him to meet her in her dressing room.

By the third and final film in 1981, Backus was suffering from Parkinson's disease and his participation was limited to a cameo appearance.

In stark contrast to his usual affluent characters, he guest-starred on The Brady Bunch in 1971 as an old gold prospector, a role he also played on a Gilligan's Island episode.

He also appeared in "Never Con a Killer" (1977), the pilot for the ABC crime drama The Feather and Father Gang.

[citation needed] In the late 1950s, he made two novelty 45 rpm records, "Delicious" and "Cave Man".

[10] In Bowl 'Em Over with GE Bulbs (1963), a Cinécraft Productions sales training film made for the GE Large Lamp Division, Backus introduces the Mr. Magoo Soft White light bulb TV advertising campaign for Fall 1963.

On July 3, 1989, Backus died in Los Angeles from complications of pneumonia after suffering from Parkinson's disease for many years.