The 1971 event that ended the US dollar’s direct convertibility into gold for foreign governments was the Nixon Shock.
On 15 August 1971, President Richard Nixon announced that the United States would suspend the dollar’s convertibility into gold. Under the Bretton Woods system, foreign central banks could exchange dollars for gold at $35 per troy ounce. Growing US balance-of-payments problems and pressure on American gold reserves made that arrangement increasingly difficult to maintain.
The announcement also introduced wage and price controls and an import surcharge. The Smithsonian Agreement later attempted to preserve a revised fixed-exchange system, but the arrangement broke down in 1973 as major currencies moved toward floating exchange rates.
The Nixon Shock did not abolish the dollar or make it worthless. It ended the dollar’s official gold link and helped create the modern era of largely fiat currencies, whose value is not fixed to a physical metal.