The show featured Sada Thompson and James Broderick as Kate and Doug Lawrence, a happily married middle-class couple living in Pasadena, California. Doug is an independent lawyer, and Kate was a housewife (she would eventually go back to school herself). They had three children: Nancy (portrayed by Elayne Heilveil in the original mini-series and later by Meredith Baxter Birney), Willie (Gary Frank), and Letitia, nicknamed "Buddy" (Kristy McNichol). (There was another son, Timothy, who had died five years previous to the series' beginning.) The show raised the profile of all of its featured actors during its run and, in particular, catapulted McNichol to stardom.
The show attempted to depict the "average" family, warts and all. Storylines were very topical, and the show was one of the first to feature shows that have recently been termed as "very special episodes." In the first episode, Nancy walked in on her husband Jeff (John Rubinstein) making love to one of her friends. During the second season she and Jeff divorced, but Jeff would continue to appear regularly as an active father, as well as finding himself involved in more of the Lawrence family's affairs. Other topical storylines included Kate having to deal with the possibility that she had breast cancer, as well as Buddy dealing with advances from boys. In the later seasons, there were instances in which Buddy had to decide whether or not to have sex; she always chose to wait, most notably in an episode with guest star Leif Garrett, who was a teen idol at the time. Another topical episode dealt with Buddy's friendship with a teacher who was revealed to be a lesbian. Family also dealt with alcoholism (Doug's sister; Buddy's old friend) as well as adoption, when the family adopted a girl named Annie Cooper (Quinn Cummings). One episode in 1979 (directed by actress Joanne Woodward) guest-starred Henry Fonda as a visiting elderly relative who was beginning to experience senility and memory loss.