Everything that existed in hard money.

This line is a bit odd.. everything that existed in hard money.
maybe in other words it's everything that was related to hard money?
or that everything that existed (thanks to the use) in hard money?

when countries realized how lucrative business it might be to have a monopoly on money creation, they forbade Free Banking. The currently valid system, Central Banking, was established. So-called fiat money was created. It is a denial of everything that existed in hard money.