in various TV series, including Omnibus and Robert Montgomery Presents. He continued guest-starring in series during the 1960s including playing The Major in "Five Characters in Search of an Exit", a 1961 episode of The Twilight Zone; Windom considered this guest appearance as his West Coast television debut. He later reported that Richard Widmark was originally offered the role, but when Widmark learned that the pay was only to be $1,000, he turned it down. Actress Susan Harrison, who played the Ballerina, got first billing, while Windom got second. His first leading role came in the sitcom The Farmer's Daughter (1963–1966), a series based on the 1947 film about a young Minnesota woman (played by Inger Stevens) who became the housekeeper for a widowed congressman (Windom). It ran for three seasons. Windom's first role in film was alongside Gregory Peck in the Oscar-winning movie To Kill a Mockingbird (1962); he played Horace Gilmer, the prosecutor of Tom Robinson (Brock Peters). He appeared on The Donna Reed Show, Gunsmoke, Star Trek, and Ironside. In Star Trek, he played Commodore Matt Decker, commander of the doomed USS Constellation in the 1967 episode "The Doomsday Machine", a role he reprised nearly 40 years later for Star Trek: New Voyages. He played a recurring role (3 episodes) in "The Invaders" in 1967. In 1968, Windom guest-starred on Ironside in the episode "Trip to Hashbury." Also, in 1968, Windom starred alongside Peter Falk and Gene Barry in the TV movie Prescription: Murder, the pilot for the TV series Columbo. He starred in another edition of the series titled "Short Fuse" in 1972. In 1971 he played a supporting role alongside Jimmy Stewart, George Kennedy and Kurt Russell in the Columbia production Fools' Parade. Windom starred with Frank Sinatra in the film The Detective (1968), playing a homophobic killer, a role appreciated in The New York Times. The following year, he had the lead role as cartoonist John Monroe in the sitcom My World and Welcome to It. Although the series only aired for one season, he won the 1970 Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series. In 1971, Windom guest-starred as a victim of blackmail on Cannon in the episode "Death Chain". Later, in 1975, he guest-starred as George Kane, a desperate drug dealer, in the series finale of Mannix in the episode "Hardball". In 1980, he appeared as Amos Krebbs,