The 1873 financial crash that helped begin the Long Depression was the Panic of 1873.
The panic followed a speculative boom in railways, construction, and property. In the United States, the failure of Jay Cooke & Company in September 1873 undermined confidence because the firm had heavily promoted Northern Pacific Railway bonds. The New York Stock Exchange closed temporarily, an unusual response that reflected the severity of the liquidity crisis.
Financial distress spread across the Atlantic, affecting banks and businesses in Europe and North America. The ensuing period of weak prices and slow growth is called the Long Depression. Historians debate its exact dates and severity, but the panic is widely treated as a major turning point in the nineteenth-century global economy.
The Panic of 1873 is not identical to the later Great Depression. It also was not simply a railway failure: railway speculation was one major link in a larger chain involving credit, banks, and securities markets.