US federal funds rate hit 19.39 percent in April 1980. As a result long-term state bond did very well for their owners as inflation came down. My mom told stories about "Massachusetts Nines" with legendary 9% yields.

Utilities and co-ops issued ~15% paper which also did extremely well for those who purchased it in the early 80s.

Know offhand what the 30-year yielded back in '80?

For reference, the 30 is now at about 100bp less than shorter treasuries:

https://www.marketwatch.com/market-data/rates

~11% (https://www.govinfo.gov/content/pkg/ERP-2012/pdf/ERP-2012-ta...)

Sure, back then. But I’m guessing these are not 50+ year maturities still paying out.