Kennedy had undergone emergency triple bypass surgery in 2002. That same year, he and his late wife moved to Idaho to be closer to their daughter and her family, though he still was involved in occasional film projects.
His biggest acting acclaim came in Cool Hand Luke, a 1967 film about a rebellious war hero played by Paul Newman who is bent on bucking the system as a prisoner on a Southern chain gang. Kennedy played the role of Dragline, the chain-gang boss who goes from Luke's No. 1 nemesis to his biggest disciple as Newman's character takes on folk hero status among fellow inmates. The movie garnered four Academy Award nominations, and Kennedy was named best supporting actor.
Kennedy then carved out a niche as one of Hollywood's most recognizable supporting actors. He had parts in several action flicks in the 1970s, played Leslie Nielsen's sidekick in the Naked Gun spoofs and was J.R. Ewing's business rival in the final seasons of primetime soap opera Dallas.
One of his strongest supporting roles was in the hit 1970 film Airport, which spurred the run of 1970s disaster pictures. Kennedy played Joe Patroni, a no-nonsense, cigar-chomping troubleshooter who stubbornly guides a jetliner stuck on a snow-clogged runway out of harm's way. The film spawned several sequels (Kennedy was in all of them) and landed Kennedy a Golden Globe nomination.
Kennedy said his acting ambitions were cemented when he was a young child.
"I remember listening to a radio program when I was young and it made me feel good and I remember telling my mom that I wanted to make people feel the way this radio program made me feel," Kennedy said in 1995.
"I got some great breaks, and I wound up being an actor."
His film career began to take flight in the early 1960s. He starred in Charade, The Dirty Dozen and Guns of the Magnificent Seven. Kennedy once called Charade the favorite movie in which he appeared.
Among his later credits was a small role in Wim Wenders' 2005 film, Don't Come Knocking, and a guest stint in 2003 on CBS daytime serial The Young and the Restless, where he played Victor Newman's (Eric Braeden) father, Albert Miller. Kennedy's last on-screen role was in the 2014 remake of The Gambler.
Kennedy was born in New York in 1925. He started acting at the age of 2 when he joined a touring company production of "Bringing up Father." Five years later, he became a disc jockey with a kids radio show. He enlisted in the Army at 17 and served in World War II, opening the first Army Information Office that provided technical assistance to films and TV shows. Kennedy spent 16 years in the Army and left as a captain. After his Army stint, Kennedy made his television debut in The Phil Silvers Show in 1955 and had a variety of guest appearances in the Westerns Have Gun, Will Travel, Cheyenne and Gunsmoke.
In later years, Kennedy became an advocate for adopted children. He had four adopted children, including his granddaughter Taylor, whose mother, also adopted by Kennedy, had become addicted to drugs and alcohol.
"Don't let the fact that you're 77 or 70 get in your way. Don't let the fact that you're a single parent and you want to adopt get in your way," Kennedy said in a Fox interview in 2002. "That kid, some place right now, cold and wet, needs somebody to say, "I love you, kid, good night.'"