Causes of the Great Depression

They are 4 big causes of the great depression:
1-The overproduction: U.S.A produce a lot of textiles, cars, medicines and weapons. This products were useless after the First War World.
2-Stock Market: The shares of wall street have low prices.
3-Banking Crisis: All the people were taking out there money of the banks, the banks don't have the capacity to give the money to the people thats why they broke.
4-Unemployment: The unemployment waas of a 30%.