Which stock exchange crash on May 9, 1873, helped start the Long Depression?

The Vienna Stock Exchange crash on May 9, 1873, helped start the Long Depression.

The date became known as Black Friday in Austria. A speculative boom in railways, construction, and other enterprises had encouraged rapid share-price increases. When confidence broke, investors rushed to sell, and many companies failed. The panic soon spread through European financial markets.

The crisis reached the United States later in 1873, when the failure of the banking firm Jay Cooke & Company helped trigger a panic and the temporary closure of the New York Stock Exchange. The resulting downturn included bank failures, falling prices, industrial contraction, and high unemployment.

Historians debate the exact boundaries and causes of the Long Depression, and the downturn did not affect every country in exactly the same way. The Vienna crash is nevertheless widely treated as the opening shock of the international financial crisis of 1873.