Going off the gold standard gave the government new tools to steer the economy. If you're not tied to gold, you can adjust the amount of money in the economy if you need to. You can adjust interest rates.
The gold standard (in economics) refers to a type of monetary system where the currency of a country is backed directly by the national gold reserves. In theory, it is possible for anyone in such a system to go to a bank and exchange a sum of money for a specific amount of gold.