Belushi's first big break as a comedian occurred in 1971, when he joined the Second City comedy troop in Chicago. Thanks to his uncanny caricature of singer Joe Cocker's intense and jerky stage presence, he participated in National Lampoon's "Lemmings" stage show in 1972 (which also featured future Saturday Night Live performer Chevy Chase).
He achieved national fame with his work on Saturday Night Live, which he joined as one of the original cast members in 1975. He left Saturday Night Live to pursue a film career, and he appeared in a number of movies, including The Blues Brothers (with Dan Aykroyd) and Animal House.
He was also known to indulge in bouts of drinking and involvement with drugs which eventually cost him his life. John was found dead on March 5, 1982 in a hotel room. The cause of death was a lethal injection of cocaine and heroin. There was some suspicion of foul play by his companion and drug dealer at the time, Cathy Smith.