Cherry Picking The Diamonds From The Stock Market

What was the leadnig cause to the great depression stock market crash in 1929?

In 1929 the stock market crashed. Therefor leading to the great depression and horrible poverty. Why did the stock market crash?
I dont have a test. I read books and in my book i am currently reading sea biscut. It never said why the stock market crashed so i was just wondering

The leading cause of the Great Depression was agriculture. Soil erosion caused great dust bowls in the U.S. and throughout the world. 90% of the country lived on farms and ranches and decreased output caused poverty. The other 10% of the population were mostly involved in goods and services for the farming community. The Great Depression started well ahead of the Stock Market Crash. The market crash was an inevitable result of a failing economy. Nothing did much to solve the problem until military spending preceding World War II stimulated the entire economy.