The worldwide financial panic that began in September 1873 was the Panic of 1873.
The panic started in Vienna and spread to other financial centers, including Berlin and New York. In the United States, the failure of the investment firm Jay Cooke & Company in September 1873 helped trigger a banking crisis and a suspension of trading on the New York Stock Exchange.
The downturn was connected to railway speculation, excessive borrowing, falling agricultural prices, and financial weaknesses created during the post-Civil War expansion. The resulting depression was long and severe in several countries. In the United States, it contributed to business failures, unemployment, and labor unrest.
The event is sometimes called the Long Depression, but those terms are not identical in every historical source. “Panic of 1873” refers specifically to the financial crisis, while “Long Depression” generally describes the prolonged economic downturn that followed.