I think we went off the gold standard many years before JFK’s administration.
Nixon took us off the gold standard.
Between 1946 and 1971 countries operated under the Bretton Woods system. Under this further modification of the gold standard, most countries settled their international balances in U.S. dollars, but the U.S. government promised to redeem other central banks' holdings of dollars for gold at a fixed rate of $35 per ounce. However, persistent U.S. balance-of-payments deficits steadily reduced U.S. gold reserves, reducing confidence in the ability of the United States to redeem its currency in gold. Finally, on August 15, 1971, President Nixon announced that the United States would no longer redeem currency for gold. This was the final step in abandoning the gold standard.