Under the gold standard, a government is limited both legally and practically as to how much paper money it can print. As recently as the Lyndon Johnson administration, the U.S. could print paper dollars equal only to four times the value of the nation's gold reserves.
Under the gold standard, governments that print too much paper money risk runs on their gold reserves. Runs occur as holders of the paper seek to convert to gold before the vaults are empty.
A run on the dollar is what happened in the late 1960s, which culminated in President Richard Nixon closing the gold window in 1971.
"Closing the gold window" is a euphemism for the U.S. defaulting on its promise to other countries to redeem dollars for gold. As an alternative, Nixon could have devalued the dollar and continued to redeem. In effect, he chose a one hundred percent devaluation, a de facto default on the promise to redeem.
In the 34 years before Nixon closed the gold window, the money supply in the U.S. grew less than two fold. In the 34 years after Nixon's action, the money supply expanded 13 fold and the Fed Reserve has taken the US gold.