Look over Keith's IMDB page when you get a chance...the man was all over the map and had a much more extensive career than his Disney stuff or FAMILY AFFAIR, which he said he took because its production was arranged like MY THREE SONS for Fred MacMurray: he could spend just over two months a year to make a season's worth of shows and go on to other projects.
Keith was also a family man, with a total of seven kids (three adopted), which probably explained his attraction to a show like FAMILY AFFAIR. His later life turned tragic when his troubled daughter Daisy committed suicide in 1997, at a point when Keith's health and finances were also in great peril. Two months after his daughter's death, he took his own life at the age of 75
The personal quotes section on the IMDB page reveal a man with strong opinions and a forcefully articulated personal code...
A couple of years after THE PARENT TRAP, Keith scared the Bejeezus out of me when he portrayed the unhinged husband of Vera Miles in the pilot episode of THE FUGITIVE. You can check it out here: