On March 14, 1900, the Gold Standard Act was ratified, placing United States currency on a gold standard. Thus ended the country’s weird experiments in bimetallism, established in 1792 when Treasury Secretary Alexander Hamilton urged Congress to fix the ratio of gold and silver at 15:1.
The gold standard itself ended on April 25, 1933, and its last vestiges were scrapped when President Richard Nixon closed the foreign gold exchange window in 1971, thereby ending the Bretton-Woods international monetary system.