You have your causality backwards, check the dates:

https://en.wikipedia.org/wiki/Wall_Street_Crash_of_1929

https://en.wikipedia.org/wiki/Executive_Order_6102

The US went off the gold standard in 1933 because of the crash of 1929, which (obviously) happened under the gold standard. It was part of an extreme but ultimately successful project to re-mobilize the economy. Although the dramatic federally-directed transformation seems to have left a lot of scars on US politics.