What was the name of the 1929 U.S. stock-market collapse that began on Black Thursday?

The 1929 U.S. stock-market collapse that began on Black Thursday was the Wall Street Crash of 1929.

The crash followed a speculative boom in U.S. shares during the 1920s. Investors increasingly bought stocks on margin, borrowing money to purchase securities. As confidence weakened, selling accelerated. The New York Stock Exchange experienced especially heavy trading on October 24, 1929, known as Black Thursday, and again on October 29, known as Black Tuesday.

The crash did not by itself cause every feature of the Great Depression, but it severely damaged confidence, wealth, and financial institutions. U.S. stock prices continued falling after October 1929, with the Dow Jones Industrial Average reaching its low in 1932. A common mix-up is treating Black Tuesday as the entire crash; it was one of the crash's most dramatic days, while the broader event is called the Wall Street Crash of 1929.