According to the National Center for Policy Analysis, the official end to the U.S. Gold Standard came in 1971 when President Richard Nixon announced that the government would no longer redeem dollars for gold. This political move was the last in a line of policies designed to increase purchasing power.
President Nixon's 1971 declaration meant that the value of the American dollar would no longer be tied to a specific weight of gold but completely determined by government policy. Prior to this action, the First World War and the Great Depression had already weakened the gold standard. The United States' involvement in WWI led the Federal Reserve to issue more paper money than there was gold in the U.S. Treasury. In 1934, President Roosevelt significantly raised the price of gold and prohibited its private ownership.