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, which lasted from 1929 to 1941, was a severe economic downturn caused by an overly-confident, over-extended stock market and a drought that struck the South. In an attempt to end the Great Depression, the U.S. government took unprecedented direct action to help stimulate the economy.