The phrase Black Tuesday refers to October 29, 1929, five days after the United States stock market crash of Black Thursday, when general panic set in that everyone with investments in the market tried to pull out of the market at once. This week and its aftermath marked the start of the Great Depression in the United States. While Black Tuesday is often cited as the worst day in Stock Market history, in terms of percentage loss, the largest occurred on December 12, 1914.

So the answer is....not exactly. Black Tuesday didnt cause the Great Depression. The depresion was caused by everyone pulling their stocks out of the market the Thursday before. Black tuesday is pretty much the day that people noticed that they had lost all thir money and realized how bad things were about to get.

Black Tuesday was more of a catalyst than the actual cause. I was the bursting of a bubble. There were a number of factors that lead to the Great Depression. Poor banking regulation, over confidence in the stock markets, protectionist trade practices thought the world. Black Tuesday created the inertia that brought the economic house of cards down.