What event is commonly regarded as the starting point of the Panic of 1873?

The Vienna Stock Exchange crash is commonly regarded as the starting point of the Panic of 1873.

On May 9, 1873, a speculative boom in Austria-Hungary ended abruptly at the Vienna Stock Exchange. The collapse followed years of rapid railway construction, property speculation, easy credit, and aggressive promotion of new companies.

Financial stress then spread internationally. The failure of the investment firm Jay Cooke & Company in the United States in September 1873 helped trigger a major American banking panic, but it came after the Vienna collapse rather than before it.

The resulting downturn was unusually long and became known as the Long Depression in some historical accounts. Its effects included bank failures, falling prices, reduced investment, and prolonged weakness in industrial economies. The event is sometimes confused with the later U.S. Panic of 1907.