Which U.S. investment bank's failure intensified the Panic of 1873?

The failure of Jay Cooke & Company intensified the Panic of 1873 in the United States.

Jay Cooke & Company was a major American investment bank that helped finance Union debt during the Civil War and later promoted railroad construction. On 18 September 1873, it suspended payments after investors lost confidence in its Northern Pacific Railway financing.

The collapse helped trigger a wider banking panic. The New York Stock Exchange closed temporarily, credit contracted, and railroad failures spread through the economy. The downturn lasted for years and is associated with the Long Depression.

Jay Cooke's failure was not the original cause of every event in the worldwide crisis. Earlier turmoil in Europe, especially the Vienna Stock Exchange crash of May 1873, had already exposed the dangers of speculation and fragile credit.