McLean Stevenson began in show business at age 31. During the 1960s, he worked in night clubs and comedy cabarets, did summer stock theater and some television before moving to Hollywood, where he worked as a comedy writer for Tom Smothers. He eventually began acting in sketches. Mr. Stevenson is best known as the fumbling commanding officer and chief surgeon, Lt. Colonel Henry Blake, on the CBS television series M*A*S*H. Over a period of thirty years, he also appeared on a number of television series and was a regular guest star on Johnny Carson's The Tonight Show Starring Johnny Carson and the game show The Hollywood Squares.
McLean's first name came from McLean County, Illinois, where he was born and raised. Grandfather was Vice-President Adlei E. Stevenson, who served under President Grover Cleveland from 1893 to 1897. Cousin of Democratic presidential candidate (1952 and 1956) Adlai Stevenson. Stevenson died one day before Roger Bowen. Bowen played the role of Col. Henry Blake in the movie MASH; Stevenson played the role on TV. Interred at Forest Lawn (Hollywood Hills), Hollywood, California, USA, in the Columbarium of Valor. To research for his role as an army surgeon on M*A*S*H, McLean Stevenson thoroughly studied a book on the history of medicine loaned from Alan Alda. Months later, that knowledge proved extremely useful when he came upon a person who was critically wounded in a car accident. Drawing on his research, he was able to keep the person alive until help arrived. Brother of Ann Whitney. Was still in the hospital recovering from surgery when he suddenly went into cardiac arrest and died. In the season finale of the first season of M*A*S*H, the name of his character's (Henry Blake) wife is Mildred. In the second season, her name was changed to Lorraine. When he was replaced by Harry Morgan, Morgan's character, Colonel Potter, had a wife named Mildred. Served in the Navy After the news of Col. Blake's death on M*A*S*H shocked the world, the very next night on "The Carol Burnett Show" (1967), the opening shot was of Henry Blake in a smoking raft, waving his arms, hollering, "I'm OK! I'm OK!" One legacy of Stevenson is a word coined from his first name. "McLeaning" is a term used in media, especially television, to refer to cases when a character is killed off because the actor who played him decided to leave the show, as happened to Henry Blake when McLean Stevenson left M*A*S*H. The unexpected death of Stevenson's Henry Blake character from M*A*S*H (1972) caused such a strong fan backlash, with countless letters of hate mail being received over the character's death, that the show's writers and producers all agreed that in the future, should one of their actors wish to leave, they would never give that actor's character a tragic send off.