My Three Sons is a CBS\ABC network sitcom that starred Fred MacMurray, William Frawley, William Demarest, Tim Considine, Don Grady, Stanley Livingston, Barry Livingston, Meredith MaCrae, Tina Cole, Beverly Garland, Dawn Lyn & Ronne Troup.
The show first aired on the ABC network from September 29, 1960 to May 20, 1965 and was filmed in black & white. After the series moved to the CBS network on September 16, 1965, it was filmed in color until the series' end on April 13, 1972 after 12 seasons and 380 episodes.
The show originally featured William Frawley as the boys' live-in maternal grandfather, Bub O'Casey. William Demarest (who portrayed Bub's brother) replaced Frawley in 1965 due to his health issues.
In September of 1965, the eldest son Mike got married and his character was written out of the show and in order to keep the emphasis on "three sons", a new son named Ernie was adopted.
In the show's final years, Steven Douglas remarried and adopted his new wife's young daughter Dorothy (AKA "Dodie").