The Bretton Woods Monetary Conference, held in Bretton, was one of the most significant events in history that helped to standardize the Forex Market as we have today.
After World War II, the G3 comprising the United States, Great Britain, and France met at the United Nations Monetary and Financial Conference in Bretton Woods to fashion a new global economic order. The chosen location at the time was simply because the US being the only country not heavily affected by the war. Most of the major European countries were in shambles during this period. WWI transformed the US dollar from a failing currency after the stock market crash of 1929 to a yardstick currency by which other international currencies would subsequently be compared against.
Following this, other countries were required to establish an exchange rate based on the relative exchange rate of the US Dollar to the home currency. Nevertheless, the US dollar could not subdue gold as it held the highest amount of substantial reserves globally. To this end, they instead attached a higher importance to gold against the dollar exchange rate. The dollar as the standard unit of exchange would lead to the creation of a free-floating system.