The primary cause of the Panic of 1929 in the United States was a combination of speculative investments in the stock market and unsustainable economic practices. Throughout the 1920s, known as the Roaring Twenties, there was a boom in stock market investments, often leveraged with borrowed money. As stock prices surged, investors engaged in rampant speculation, ignoring warning signs of economic instability. Ultimately, on October 29, 1929, known as Black Tuesday, the stock market crashed, leading to financial chaos, bank failures, and widespread unemployment. This event marked the beginning of the Great Depression, profoundly impacting the U.S. and global economies.