They weren't even exactly stable if you look at data between 1800 and the 1930s , though: https://www.officialdata.org/us/inflation/1800?amount=1#:~:text=Value

They weren't even exactly stable if you look at data between 1800 and the 1930s , though: https://www.officialdata.org/us/inflation/1800?amount=1#:~:text=Value%20of%20%241%20from%201800,cumulative%20price%20increase%20of%202%2C295.52%25 https://www.officialdata.org/us/inflation/1800?amount=1#:~:t.... or even in the 18th century: https://www.in2013dollars.com/UK-inflation https://www.in2013dollars.com/UK-inflation The counter-swings just created an illusion of longterm stability. But it definitely didn't feel that way for people living on the ground (of course a lot of that is down to unstable food supply and not just the monetary system. Not that it was avoidable, you can't really have a fiat currency without a stable and somewhat reliable government anyway).