Vienna is associated with the first major shock of the Panic of 1873. On 9 May 1873, the Vienna Stock Exchange crashed in an event known as Black Friday, helping ignite a financial crisis that spread through Europe and later to the United States.
The boom before the crash had been supported by railway speculation, rapid industrial expansion, and abundant credit. When confidence broke, banks and companies failed, construction slowed, and investors began selling assets. The crisis moved across borders because financial institutions and markets were increasingly connected.
In the United States, the failure of the banking firm Jay Cooke and Company in September 1873 contributed to the collapse of confidence and helped close the New York Stock Exchange temporarily. Historians debate the boundaries and causes of the Long Depression, but Vienna's May crash is widely recognized as its opening financial shock.