David Bruce Cassidy is a former teen idol, best known for his role as 
Keith Partridge in the 1970s musical/sitcom The Partridge Family on
ABC (1970 to 1974). He still performs today.

 
Season six consists of 28 episodes (Sep.13, 1987 – May 1, 1988) 

The sitcom Family Ties aired on NBC from September 22, 1982 until
May 14, 1989 for a total of seven seasons. It won multiple awards,
including three consecutive Emmy Awards for Michael J. Fox as
Outstanding Lead Actor in a Comedy Series.

 

                Milo O’Shea (June 2, 1926 – April 2, 2013)

New York (AP) – Irish character actor Milo O’Shea had roles in the NBC
television series “The West Wing” (1999 – 2006) and was often cast as
priests, playing one in the NBC sitcom “Cheers” (1982 – 1993). One of
his most memorable supporting roles was as a judge in the Sidney Lumet
directed 1982 film “The Verdict” starring Paul Newman. O’Shea also had
a career on Broadway, during which he earned two Tony nominations. He
died on Tuesday following a short illness.  

Mary Lucy Denise "Marilu" Henner is best known for her role as
Elaine O’Connor Nardo on the ABC-TV sitcom Taxi, 1978 to 1983.

Henner began teaching dance classes at her family’s studio
when she was 14.

From episode 12 of the second season, "Elaine’s Secret Admirer"
(1979).

Gabriel W. "Gabe" Kaplan is a comedian, actor, poker commentator,
and professional poker player. He is best remembered starring in the
ABC-TV sitcom “Welcome Back Kotter” (1975 to 1979.

Although he originally wanted to become a baseball star, he eventually
began working as a bellman and stand-up comedian.