What happened October 29, 1929?

On October 29, 1929, Black Tuesday hit Wall Street as investors traded some 16 million shares on the New York Stock Exchange in a single day. Billions of dollars were lost, wiping out thousands of investors. In the aftermath of Black Tuesday, America and the rest of the industrialized world spiraled downward into the Great Depression (1929-39), the deepest and longest-lasting economic downturn in the history of the Western industrialized world up to that time.