Roosevelt did one thing smart, though. Even while he was spending like a drunken sailor, he was putting the dollar on a strong footing, backed by gold, which was no longer traded and speculated. That way, though the dollar was seriously devalued, it had a mechanism to bring it back. Obama, however, is not interested in doing the same. So the dollar is no longer the world currency it once was.
No, the dollar was no longer backed by gold after Roosevelt was through with it. Previously, Americans who had paper currency, called "Gold Notes" could trade in the currency for a fixed amount of gold. Roosevelt, by legislation, forbade Americans from owning gold at all.
He wanted the value of the dollar to decrease, to help debtors - especially farmers - and hurt creditors. But there wasn't much inflation in the general economy because it was very soft.