The last gold standard
The last gold standard was set at the Bretton Woods conference in 1944, which also created the International Monetary Fund and The World Bank while setting the broader postwar standard for international financial relations.
Forty-four nations at the conference adopted the gold standard, believing that it would create exchange rate stability, prevent devaluations of currencies, and help drive economic growth.
By 1971, the U.S. was struggling to maintain the proper supply of dollars to adhere to the gold standard. It also faced deficits that led to foreign-held dollars that exceeded the U.S.'s own supply of gold, meaning it could not redeem dollars for gold if the international supply had been called.
As a result, Richard Nixon ended the dollar's convertibility to gold, effectively ending the gold standard. At this point, it seems unlikely to return since most countries prefer to give central banks control of the money supply and monetary system.