"In charge of its monetary policy" can mean a hundred different things, so that is impossible to answer directly. While a centralized (and government controlled, regardless of what it would have you believe) banking system seems as obvious today as a national military, it is a relatively modern invention. The Fed itself didn't exist until 1913. USA was on the gold standard until 1933. The US dollar wasn't a fiat currency until 1971.
Some of this country's greatest achievements have come in a system where the government still had full legislative, executive and judicial powers but had to operate under basic rules like not being able to print money for themselves whenever they felt like it.
Ok, that is different though... you are arguing the US CHANGED their policy, and you don't like the way they changed it.
That is different than saying they were not in control of their monetary policy... they have always been in control, you just liked the old monetary policy better
Have they always been in control? Yes, for the entire existence of the US it has been legally capable of creating a US Dollar and of turning it into a fiat currency.
However, for large swaths of the time the US has been around that has not been politically feasible, and I'm not sure it would have been economically feasible, fiat currencies seem to have taken a while to gain stability and acceptance.
For a large period of time the US was on a gold standard and de facto did not have control over monetary policy. It doesn't matter much that they technically had power if they didn't use it.
Yes, Bretton Woods isn't a good example of a time where the US literally lacked control over monetary policy.
However, the GP stated that countries without control of monetary policy cease to exist. For the purposes of addressing that statement a period of >30 years where the US decided not to exercise any control seems nearly as good of a counter-example as a period where they literally had no control.
