As far as the origins of Polish jokes, there are a couple of theories – but if you want to know about the prevalence of Polish jokes in the 70s, look no further than prime time TV.

Mainstream acceptance and popularity of 'the Polish joke' probably started with Rowan & Martin's Laugh-In. I can't find a clip from the show but I found this issue of "Laugh-In Magazine" at archive.org: https://archive.org/details/Laugh-in_01_1968 . Just flip to page 15 and, if it's 1968, you're probably the funny guy at the dinner table (assuming you're not in the company of Poles). Sock it to me!

EDITORIAL STATEMENT Let's Let Poland Alone! STOP POLISH JOKES!

Laugh-In Magazine calls upon every American to STOP Jokes like:

Why does a Polish race track driver make eight pit stops? Two for gas . . . six for directions.

Why is a Polish Wedding Cake made out of garbage? To keep the flies off the bride.

What's different about a Polish Tank? It's the only one with backup lights.

What's the Capital of Poland? About $37.50.

Some thought these jokes were distasteful. One actor and guest on Laugh-In (Joseph Cotten) said he liked the show - except the Polish jokes. He told the "Burbank jokes" while he was on the show (these were already a recurring gag).

Here's a clip from the popular TV prime time hit All In the Family, which aired from 1971-1979. https://www.youtube.com/watch?v=hSL2Y9UpEOM

That clip is telling. There's more than just a Polish joke punchline in those three minutes. It suggests to us that Poles had filled positions at all levels of American society by the 1970s. Archie Bunker, who's a kind of an 'everyman' ageing white male American, out of place in the diverse New York City of the 70s, is obviously surprised and uncomfortable to learn that the police officer is Polish. This clip also illustrates something that always makes 'outsiders' uncomfortable – special treatment between Poles. The officer is already asking his subordinate to apologise to "Mr. Bunker," because he assumes that Archie Bunker is a friend of the Poles - his son-in-law is Polish, after all. How wrong the cop was!

As far as the origins, those are harder to explain. The web site for the documentary Polack suggests 6, starting with that uncomfortable "in-group" mentality that Archie Bunker found himself on the outside of (even if, for a moment, he was "in"):

As a category of folklore and sociology, joking is often the subconscious effort of an inside group within society to goad a fringe group into assimilating. Poles in America stayed within their communities and close to their families. Clean Protestant capitalist America feared groups that potentially owed their allegiance to a foreign power, the Pope, and didn’t strive toward the American dream, but instead were rather happy in their often dirty blue-collar jobs.

Additional theories for the source of the joke include: 1. rival ethnic groups importing old-world hostilities; 2. the Polish cavalry with swords and fancy costumes attacking Nazi tanks in WW2; 3. difficulty for Polish-Americans to learn English because their native tongue was slavic; 4. categorization of Poles as Communists; and 5. an early Polish legislative policy called the Liberum Veto, in which any member of congress could nullify the entire session, which lead to easy pay-offs and the inability of Poland to centralize its government against hostile neighbors.

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