What was the name of the catastrophic 1929 US stock-market collapse that began on Black Tuesday?

The catastrophic 1929 US stock-market collapse was the Wall Street Crash of 1929.

The crash followed years of rapidly rising share prices, widespread speculation, and extensive buying on margin. On October 24, 1929, often called Black Thursday, heavy selling shook the New York Stock Exchange. A temporary recovery effort did not prevent another wave of selling on October 28 and October 29, known as Black Tuesday.

The Dow Jones Industrial Average fell sharply from its September 1929 peak and eventually lost almost 89% of its value before reaching a low in July 1932. The crash damaged banks, businesses, and investors, but it was not the sole cause of the Great Depression. Banking failures, falling demand, debt, and policy choices deepened the worldwide economic crisis.

A common mix-up is treating Black Tuesday as the entire event. Black Tuesday was one especially severe day within the broader Wall Street Crash of 1929. The New York Stock Exchange crash also differed from the later economic depression that followed it.