Which event names the severe U.S. stock-market decline of October 1907?

The severe U.S. stock-market decline of October 1907 is known as the Panic of 1907.

The panic began after an unsuccessful attempt to corner the stock of United Copper Company. When the scheme failed, depositors withdrew money from banks connected with the speculators, and fear spread through trust companies and financial markets. The New York Stock Exchange then suffered a sharp fall in liquidity and confidence.

J. P. Morgan helped stabilize the system by organizing emergency loans and persuading financiers to support threatened institutions. The episode exposed the weakness of the U.S. banking system, which lacked a central bank capable of supplying liquidity during a crisis.

The panic helped build political support for monetary reform. The Federal Reserve System was eventually created in 1913. The Panic of 1907 is therefore remembered both as a market crash and as an important influence on modern U.S. central banking.