The Stock Market Crash of 1929 was an economic disaster that caused depressions in every country in the world except China and the African colonies. It was caused by the stock market "bubble" that had grown during the 1920s, which finally burst.
The crash was arguably triggered by Russia's inability to repay a loan to Austria-Hungary in February, 1929. In short order, various global stock exchanges grew softer as investors grew increasingly nervous. Soon, people who owned stock started to sell in something of a panic in Paris, Vienna and Rome throughout February and into March.  Initially, the exchanges in New York, Berlin, and Richmond seemed to be holding, but as the year passed, the situation continued to deteriorate. France left the gold standard, the London exchange plunged, and finally a sellout began in Richmond. New York began sinking shortly after. Bank runs began in both countries. Finally, in June, 1929, on a day that came to be called "Swan-Dive Wednesday", the New York market simply crashed. Banks soon failed as there was no money to pay back to their customers. A global economic depression set in.
Although no single person was responsible for the resulting depression, most of the incumbent political leaders of world took the blame when their respective policies proved incapable of effectively solving the problem. In the United States, for example, President Hosea Blackford, was soundly defeated when he ran for re-election against Calvin Coolidge in 1932. In the Confederate States, it was blamed on President Burton Mitchel and his political party, the Whigs. Jake Featherston and the Freedom Party used the Confederate depression to agitate the previously content Confederate voters into electing him President.
Similar patterns played out in Britain, where the upstart Silver Shirts forced the Conservative Party to take a hard political line when they elected Winston Churchill as Prime Minister; and in France, where Action Francaise brought down the Third Republic and elevated Charles XI as king.