The John Forsythe Show

The John Forsythe Show began as a situation comedy in the fall of 1965 on NBC, but at mid-season it switched to a spy show. In the first phase of the series, John Forsythe appeared as United States Air Force veteran John Foster, who inherited the private Foster School for Girls in San Francisco, California, from his late aunt, Victoria.

Forsythe's co-stars were Elsa Lanchester as the principal, Miss Culver; Ann B. Davis, as the physical education teacher, Miss Wilson; and Guy Marks as Ed Robbins, Forsythe's aide and a former sergeant.

Actors who portrayed students included Pamelyn Ferdin as Pamela, Darlene Carr as Kathy, Page and Brooke Forsythe (Forsythe's actual daughters) as Marcia and Norma Jean, Peggy Lipton, as Joanna, Tracy Stratford as Susan, and Sara Ballantine as Janice.

When the format changed to espionage (in the February 21, 1966 episode "Funny, You Don't Look Like a Spy"), it was explained to viewers that Major Foster had been recalled to active duty as a secret agent. All the other regulars except Forsythe and Marks were dropped from the cast.

The John Forsythe Show aired on Mondays at 8 p.m. Eastern following the Hullabaloo music program and preceding Dr. Kildare. Its competition was Garry Moore's quiz program, I've Got a Secret on CBS, and the second half of the military drama Twelve O'Clock High.
From: Wikipedia.org

The John Forsythe Show opening credits