If you’re talking about the 1930’s, then The Great Depression.
The Great Depression was a severe economic depression in the United States and the world in the 1930’s. It all started from the stock market crash on October 29th, 1929, aka “Black Tuesday”. Due to to intense “buying on margin”, credit, and borrowing of money in the 1920’s, there was no money circulation in the nation.
On Black Tuesday, the world’s GDP (gross-domestic product) dropped significantly, 15% to be exact.
The Depression lasted through the 1930’s, and many nations did not recover until World War II, when production and job openings were at an all time high. President Franklin D. Roosevelt also had a lot to do with America’s recovery with his New Deal plans that got Americans back up and working.