Mitchell began acting on Broadway in the late 1930s before signing a contract with Metro-Goldwyn-Mayer and appearing in such films as Cass Timberlane (1945) and Homecoming (1948).

Once he made the transition, he was starring as Uncle Buck Cannon on the Western series, The High Chaparral (1967-1971).

Mitchell was born Cameron McDowell Mitzell on November 4, 1918,[2] in Dallastown, Pennsylvania, of Scottish and German descent, one of Rev.

Its director, Norman C. Brace, wrote Mitchell's father, saying "... your son should succeed in becoming a very fine artist for the stage, screen or radio."

Alviene school director Claude Alviene said of Mitchell "Your son, not only has exceptional dramatic ability, but the quality of his singing voice is so musical... (it) leaves little doubt of an ultimate successful career..."[11] From 1943 - 1945, Mitchell served as a bombardier with the United States Army Air Forces MOS 1035-Bombardier group during World War II.

To make ends meet, he held many jobs, including theatre ushering, mail clerking, and washing dishes in restaurants.

[14] After two years of trying and still hoping to break into acting, Mitchell wrote dozens of letters to actors, agents, and producers in 1939.

[9] The highly critical letter pointed out what Mitchell thought was Lunt's poor performance in the movie The Guardsman.

He isn't a heavy, a comic or a juvenile – he can assume any personality the role demands and play it convincingly.

[17] He also appeared in the 1939 production of The Taming of the Shrew as a member of Alfred Lunt and Lynn Fontanne's National Theater Company.

He starred in the CBS daytime radio show Grand Central Station on January 21, 1950, in the episode "Lost and Found".

He was featured with Lana Turner and Spencer Tracy in Cass Timberlane, and with Wallace Beery in The Mighty McGurk (both 1947).

[22] Mitchell moved to Columbia Pictures and had his first movie-star role as a prizefighter in the film noir Leather Gloves (1948).

[17] Mitchell reprised the role of Happy Loman in the 1951 film adaptation released by Columbia Pictures.

[24] Mitchell was contracted with 20th Century-Fox, where he had a prolific career in such films as Les Misérables (1952) as Marius, and in the comedy How to Marry a Millionaire (1953), in which he portrayed a wealthy man attempting to romance a single woman (played by Lauren Bacall).

[27] He subsequently co-starred with Marlon Brando in Désirée (1954);[28] with Gable and Jane Russell in the Western The Tall Men (1955); and the film version of the stage musical Carousel (1956).

[28] Mitchell was lent back to MGM to co-star with Doris Day and James Cagney in the musical drama Love Me or Leave Me (1955).

[30] Mitchell, who did not drink, achieved success on television starring as the former Confederate soldier, drunkard cowhand Buck Cannon in the NBC Western series, The High Chaparral which aired from 1967 to 1971.

[16] During the show's production, Mitchell was reportedly "an outspoken, hard-headed guy who has fought with all his High Chaparral colleagues and who manages to alienate just about everybody who runs into him, from fans to producers".

In later years, Mitchell appeared in villainous roles as a sheriff-turned-outlaw in Hombre (1967), a bandit in Buck and the Preacher (1972), and a Ku Klux Klan racist in The Klansman (1974).

Beginning in 1970, he intermittently filmed The Other Side of the Wind with director Orson Welles, a project that was unreleased until 2018, 24 years after his death.

[32] In 1975–1976, he portrayed Jeremiah Worth in the Swiss Family Robinson TV series,[33] and had a supporting role opposite Leo Fong in the Filipino film Enforcer from Death Row (1976).

He appeared again on Broadway in the 1978 production of The November People,[17] and the same year starred as Henry Gordon in the television miniseries adaptation of Black Beauty.

[35] Late in his career, Mitchell played a gangster for laughs in My Favorite Year (1982), a drunken ship captain in the Filipino martial-arts horror-comedy Raw Force (1982), and a police detective in the 1983 pornographic film Dixie Ray, Hollywood Star.

[36] He had a supporting role in the anthology horror films Night Train to Terror (1985) and From a Whisper to a Scream (1987), as well as roles portraying right-wing General Edwin A. Walker in Prince Jack (1985), and as Captain Alex Jansen in Space Mutiny, a 1988 South African science-fiction film that appeared as an "Experiment" in episode 820 of Mystery Science Theater 3000.

Through the end of the decade, Mitchell appeared in many low-budget, direct-to-video films, often in roles only lasting a few minutes.

His role in these productions led him to be a recurring subject, and later a running gag, on the internet film review show Best of the Worst.

[citation needed] The Wranglers cancelled Mitchell's next scheduled appearance, quickly ending his semiprofessional career.

[citation needed] In February 1974, Mitchell entered his second bankruptcy, with $2.4 million in debts contrasted against $26 in two bank accounts.

[46] On May 9, 1973, Mitchell married Margaret Brock Johnson Mozingo, whom he met when he was in Clemson, South Carolina, making The Midnight Man; their marriage took place in Puerto Rico.