[drakythe]

Banks did this before the civil war, see https://daily.jstor.org/banks-own-private-currencies-in-19th... the article doesn't go into detail, but says that congress "effectively ended the practice" after the Civil War was settled.

I suspect that if any bank tried to push out their own Crypto the Fed would have /Questions/ for them and in general it wouldn't work out well for the bank in question.