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.
Events Leading up to the Great Depression. The Great Depression was a worldwide economic downturn that began in the fall of 1929 and did not end in many places until the Second World War. It was triggered in large part by a sudden crash of the American stock market on October 29, a day widely known as Black Tuesday.