The 1873 financial crisis that began with a Vienna stock-market crash and helped start a long depression was the Panic of 1873.
The crisis followed a period of rapid railway construction and speculative investment in Europe and North America. On May 9, 1873, the Vienna Stock Exchange crashed, an event known as Black Friday in Austria. Banking failures and falling asset prices then spread through connected markets.
The United States experienced its own severe phase in September 1873 when the investment bank Jay Cooke & Company failed. The New York Stock Exchange closed temporarily, and railway companies faced falling demand, debt problems, and bankruptcies.
The downturn became known in the United States as the Long Depression. It lasted much longer than many modern recessions, although historians debate its exact end date and whether it should be called a depression in every affected country.