Under the Bretton Woods Agreement of 1944 the US government undertook to redeem its dollars at $35 (£23) for an ounce of gold. US gold holdings then stood at 574m ounces, more than 50% of the world's total, worth just over $20bn at that conversion rate.

By anchoring the dollar to a defined unit of gold, the government was prevented from increasing the number of dollars in issue without a corresponding increase in its gold holdings.