The Panic of 1873 began in Vienna with a stock-exchange crash that spread through Europe.
The Vienna Stock Exchange crash occurred in May 1873, after years of rapid railway construction, property speculation, and easy credit. When confidence broke, share prices collapsed and many speculative companies failed. The financial shock spread through interconnected European markets and then reached the United States.
In the United States, the failure of the banking firm Jay Cooke & Company in September 1873 helped trigger a severe panic. The New York Stock Exchange closed temporarily, an unusual emergency measure at the time. The downturn contributed to a long period of deflation and unemployment often called the Long Depression.
The Panic of 1873 had multiple causes, including overinvestment, monetary pressures, and fragile banks. Vienna is the answer because the first major exchange collapse associated with the panic occurred there, not because every later phase of the crisis began in the same location.