The financial panic triggered after Jay Cooke and Company failed in 1873 was the Panic of 1873.
Jay Cooke and Company, a major American investment bank, suspended operations on September 18, 1873. It had heavily promoted bonds for the Northern Pacific Railway, and difficulties in railroad finance helped undermine confidence. The New York Stock Exchange closed for the first time in its history, from September 20 to September 29.
The panic spread through banking and railway markets, producing a long economic depression in the United States. Europe also faced financial stress, including the Vienna stock-market crash earlier in the year. Falling investment and bankruptcies contributed to years of weak growth and high unemployment.
The crisis was not caused by one company alone. Railroad overbuilding, speculative investment, tight credit, and international financial links all mattered. In Europe, the same broad downturn is often called the Long Depression, although historians debate the exact dates and severity of that label.