In KY, "Charity" bingo was legal.
You had to give part of the proceeds to charity.
Yorkshire, Merchants, 633, and Sportsman opened bingos after the gambling was shut down. There were others.

I ran the one in the Sportsman. Screw Andrews was on a federally funded vacation at Terra Haute.
I bought my equipment in KY.
We gave the charity $15 to $25 per night. (mostly $15 )
We were legal in KY.
We were legal per the Feds.

The Feds raided and closed the ones that bought their equipment at Bingo King in Little Colorado.
The charge was "Interstate Gambling."

BTW, I won a $1,000 coverall at the Merchants one night while checking out the competition.
My wife's brother worked there.