The correct answer is A stock market crash.
Due to high speculation and inflation, the stock market crashed in 1929. This day, known as Black Thursday, took place on October 29, 1929. This had a devastating effect on the American economy, as millions of people lost a significant amount of money in the stock market. Some individuals lost their entire life savings, as they had invested in throughout the 1920's. This was one of the major factors in the beginning of the Great Depression.