In 1979, Lee accepted the role of Karen Fairgate on "Knots Landing", a spin-off of the immensely popular "Dallas". Though slow to start, the series eventually became a ratings hit and became one of the longest-running American primetime dramas ever, lasting for a total of 14 seasons from 1979 - 1993. Due to her long-running tenure, Lee's alter ego is often credited as being the center of the program. Television personality Joan Rivers commented that Lee was, in theory, the "First Lady of "Knots Landing"" during her guest appearance on "The Late Show", which Rivers hosted at the time. The characters of the serial often represented what was happening in society at the time. Lee acknowledged that, saying: "Karen wanted to be a Pollyanna and wasn't ashamed of that. Remember in our society, maybe people don't remember, but remember when we could go over to other people's houses and come in through an open back door? I remember when I was a little girl and my mother and father would have people over and they'd walk into an unlocked door in our house." Lee was the only performer to appear in all of the show's 344 episodes.