The Bretton Woods Agreement was a landmark piece of financial legislation passed in the fallout of WWII. Then a new world order was created around the strength of the USD and the short-term gains of a debt-based economy. Although doomed to failure, it did allow American interests to take center stage in a new, globalized financial system.
In 1971, President Nixon permanently dislodged the USD from the gold standard, ending nearly forty years of global monetary policy in which the USD was equal to a fixed price for gold. In its place, Nixon decided to introduce a floating currency exchange system called Fiat which remains in place today.
There is a lot of hypocrisy in American political history. The Civil War had as much to do with business interests as a desire to end slavery, for example. Or take the Federal Reserve. An entity created to stabilize the consumer economy has created a nation built on debt that only serves the interests of the financial sector.