The causes of the Great Depression were numerous and interconnected, mainly starting with the stock market crash of October 1929, which erased significant wealth and investor confidence. Over-speculation, bank failures, and a subsequent reduction in consumer spending further deepened economic instability. Other factors included overproduction in agriculture and manufacturing, leading to falling prices and rising unemployment. Additionally, protectionist tariffs, including the Smoot-Hawley Tariff of 1930, exacerbated international trade issues. These combined economic vulnerabilities led to a global downturn, resulting in severe hardships for millions and necessitating substantial government intervention and reform.