The 1920's was a very prosperous time for the United States. Americans were still riding high after their win during WWl and the economy showed that. New products available to Americans made them scramble to buy them. And the best part about this was that most large products like washers and cars had an installment plan which meant that Americans didn't have to pay for the item in full, but rather pay monthly or weekly or whatever the plan was. This action was also known as buying on credit. Plus the stock market was better than ever before. People were putting money they borrowed from the banks into the ever increasing stock market. And banks also wanted a piece of the action. They would play the stock market by putting in other people's money and when they cashed in they were able to keep whatever was left over.
