I just realized that Cheers overlapped with MASH (regular episode of MASH were broadcast after the first regular episodes of Cheers showed) (I didn’t watch Cheers until much later I guess). That gives me the idea to see how few series can take us back to the early days of TV. I’ll narrow it down to scripted television just to make things interesting.
I Love Lucy (October 15, 1951 to May 6, 1957)
Gunsmoke (September 10, 1955, to March 31, 1975)
MASH (September 17, 1972 to February 28, 1983)
Cheers (September 30, 1982, to May 20, 1993)
The Simpsons (December 17, 1989 - heat-death of the universe)
Not bad - 5 series take us just about 70 years.
Gunsmoke was on the air from the Adventures of Superman era (September 19, 1952 – April 28, 1958) to the Mary Tyler Moore era (September 19, 1970 to March 19, 1977). MacGyver returned from the dead and Twin Peaks too, all during the Simpsons eon.
Wonderful World of Disney involved a lot of reruns of old movies - not really a “program”
SNL is a trickier case, but since I’ve excluded daytime TV, how about limiting it to programs in “Prime Time” (8-11 PM) - that takes care of SNL (and the Tonight Show)