Cnidaria is a phylum within Kingdom Animalia which consists of hydras, jellies (or jellyfish), sea anemones, and corals. All cnidarians are radially symmetrical, and there are two main radially symmetrical body types.
The stock market crash, on black Tuesday (October 29, 1929) began the Great Depression.
Updated August 06, 2017. The Great Depression lasted from 1929 to 1939 and was the worst economic depression in the history of the United States. Economists and historians point to the stock market crash of October 24, 1929, as the start of the downturn. But the truth is that many things caused the Great Depression, not just one single event. In the United State, the Great Depression crippled the presidency of Herbert Hoover and led to the election of Franklin D. Roosevelt in 1932