Actually, Malden and McCarthy's acting careers DO date back to the 1930's- they were both accomplished stage actors before coming to Hollywood

Karl Malden was in the opening night cast of "Golden Boy" on November 4, 1937 along with such worthies as John Garfield, Francis Farmer, Luther Adler, Elia Kazan, Art Smith, Roman Bohnen and Charlie McGraw.

Kevin McCarthy was treading the boards on Broadway back in 1938 appearing in "Abe Lincoln in Illinois".

An interesting seque was John Garfield. Odets wrote "Golden Boy" specificially for Garfield in the leading role. However, the older Luther Adler ended up opening with the part. Garfield quit the Group Theatre, went to Hollywood, and quickly became a major movie star. A number of his Group Theatre alums considered Garfield a 'sell-out' for abandoning the theatre for the movies. Until, of course, nearly everyone of them ended up in Hollywood working in films in some capacity a few years later.