My Three Sons chronicles the life of widower and aeronautical engineer Steven Douglas (Fred MacMurray) as he raises his three sons. The series originally featured William Frawley (who had first co-starred with Fred MacMurray 25 years earlier in the film Car 99) as the boys' maternal grandfather and live-in housekeeper, William Michael Francis "Bub" O'Casey. The address of the fictional home in Bryant Park was 837 Mill Street.