Premise: Frank Randolph Cady (September 8, 1915 – June 8, 2012) was an American actor best known for his recurring and popular role as storekeeper Sam Drucker in three American television series during the 1960s – "Petticoat Junction", "Green Acres", and "The Beverly Hillbillies" – and his earlier role as "Doc Williams" on "The Adventures of Ozzie and Harriet".
Hypothesis: Frank Cady made his name in American television during the middle years of his life.