In fact, he is only one of 9 people ever to win the "Triple Crown of Acting" - an Oscar, Emmy and Tony.
According to Wikipedia, "He won the Academy Award for Best Supporting Actor for 1939's Stagecoach. In 1952, he won the Best Actor Emmy (Comedy Actor category), and the following year a Tony Award for best performance by an actor, for the musical Hazel Flagg (based on the Carole Lombard film Nothing Sacred). He has two stars on the Hollywood Walk of Fame, one for his work in motion pictures at 1651 Vine Street and one for his work in television at 6100 Hollywood Boulevard."
He was born on this day, July 11, 1892. He has 106 acting credits to his name, including the Capra films:
- Lost Horizon (1937)
- Mr. Smith Goes to Washington (1939)
- It's a Wonderful Life (1946)
- Pocketful of Miracles (1961)
It turns out that 1939 was a REALLY big year in his career. According to Internet Movie Database, in addition to appearing in three movies nominated for an Academy Award for Best Picture, (Gone With the Wind, Stagecoach and Mr. Smith Goes to Washington), he appeared in two other films that received nominations in other categories: The Hunchback of Notre Dame and Only Angels Have Wings.
He won the Oscar for Best Actor in a Supporting Role for his performance in Stagecoach, as well.
Mitchell's last film appearance was in Capra's A Pocketful of Miracles in 1961, as Judge Henry G. Blake. Mitchell died Dec. 17, 1962. If he were alive today, he would be 123.
Sources: IMDB and Wikipedia.