The Gold Standard Act of the United States was passed in 1900 (approved on March 14) and established gold as the only standard for redeeming paper money, stopping bimetallism (which had allowed silver in exchange for gold). It was signed by President William McKinley.The Act made the de facto gold standard in place since the Coinage Act of 1873 (whereby debt holders could demand reimbursement in whatever metal was preferred—usually gold) a de jure gold standard alongside other major European powers at the time.

The Act fixed the value of the dollar at 25+8⁄10 grains of gold at "nine-tenths fine" (90% purity), equivalent to 23.22 grains (1.5046 grams) of pure gold.

The Gold Standard Act confirmed the United States' commitment to the gold standard by assigning gold a specific dollar value (just over $20.67 per Troy ounce). This took place after McKinley sent a team to Europe to try to make a silver agreement with France and Great Britain.

On April 19, 1933, the United States domestically abandoned the gold standard, whereafter independent states would remain assured of their US dollar holdings by an implied guarantee on their convertibility on demand: the Bretton Woods system formalized this international arrangement at the conclusion of [[]], before the Nixon shock unilaterally cancelled direct international convertibility of the US dollar to gold in 1971.