Born in Rochester, New York, his first job was writing and acting in Catskills resort shows with his brother Garson Kanin. In 1939, he was signed to a screenwriting contract at RKO.
John was born in Rochester, New York, where he started as a writer and actor in Catskills resort shows with his brother Garson Kanin. In 1939, he received a screenwriting contract from RKO.