<human>:  Why did the Great Depression start in 1929?
<bot>: The Great Depression started in 1929, because the stock market crashed that year. The crash was caused by a number of factors, including the fact that people were investing too much money in the stock market. When the stock market crashed, people lost a lot of money, and they stopped buying things. This led to a decrease in the amount of money people had to spend on other things, and this caused a chain reaction that caused the economy to crash.