Comedy is a true barometer of societal woes. Tragedy makes us feel and empathize, but comedy makes us think and adapt.
With All in the Family, Norman Lear really broke thru the stucco ceiling of suburban sitcoms such as My 3 Sons, Dick Van Dyke Show and Bewitched. Safe and sterile, sitcoms had never really challenged the audiences of the 50s and 60s. Suddenly, we had Archie, bellowing out the most vile hatred and ignorance so common in the uneducated "republican" stereotype CO'C was portraying, and doing it so deliciously, right there in our living rooms. And we laughed, by gawd we laughed.....
....but then, we asked ourselves what exactly we were laughing at. Like Shakespeare exposing antisemitism in Merchant or misogeny in Shrew, AitF was exposing American racism and intolerance and fear and sticking it into America's face, screaming from the mountain top, LOOK AT YOURSELVES!! DO YOU WANT TO BE LIKE THIS????
AitF also paved the way for more sitcoms to tell it like it was.
Enter Barney Miller (hash brownies), Mash and Mary Tyler Moore. Kotter even. And, on occasion, even WKRP hit the mark. Trumpeting the values and ethos of the modern American, the sitcom truly changed a nation. It was the golden age of the sitcom.
Alas, since the 1980s network TV has had little to compare to these classics. Other than The Simpsons of course. But without Archie, there could be no Homer. Seinfeld was unique as well, but pedestrian and slapstickish at best. Still base American treacle. NEXT!
Thank Mammon for cable. Weeds, Entourage, Californication, Lucky Louie, Louie, ConChords, etc....have been somewhat of a renaissance for the sitcom. This season, Showtime even has a sitcom about a cancer survivor called The Big C. If we can't laugh at cancer, what can we laugh at?
Funfacts about All in the Family:
I remember reading this in my early teens.

Every page a crack-up.
In 1956, O'Connor earned a master's degree in speech. So the clever wordplay was mostly self-penned.
The set chairs are in the Smithsonian.
Meanwhile, a few of you UKers have forgotten some of your own classic sitcoms: Ideal (just returned today with it's 6th season), Ab Fab, Shameless and a little known gem of brilliance entitled Absolute Power top my list. Of course, y'all can have some real stinkers too. Keeping up Appearances and Little Britain never really appealed to me, found them rather course and sophomoric. But fret not. You do own the number 2 spot behind AitF. Fawlty Towers cannot be beat by any show save for Archie and Edith.