After WW1 america was thriving, the economy was up and they had gained many allies, but you might say america got a little bit over-confident. Simply put, the US citizens had never seen the economic downfall that was to come, so when anything bad happened, it was interpreted by the citizens as terrible and life changing which lead to the stock market crash and then the great depression.
Check the explanation
The war caused the collapse and abrupt death of empires and the birth of nations; it also had some influence in modern literature and altered its culture. The effect and result of World War I was monumental and enormous.
Even if it was a branded as a devastating experience for the United Kingdom and France, they were able to restore their economic strength without any difficulty.
Another economic and political factor to note during the time of the Great Depression was the hyperinflation, which was as a result of the price of goods rapidly increasing while at the same time the value of currency was decreasing.
Then the stock market crashed, everyone pulled out their money at once, farmers and manufacturers made a surplus of goods, and thus the Great Depression happened. Kinda sad really.