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.
The Great Depression happened due to a number of reasons. It was created by a combination of a stock market crash, bad banking structure and tight monetary policy. This is why it lasted so long. The stock market peaked on September 3, 1929 with a record close of 381.17.