The 1869 US financial panic caused partly by an attempt to corner the gold market was called Black Friday.
Speculators Jay Gould and James Fisk tried to control the supply of gold available to investors outside the federal government. They hoped that a higher gold price would benefit their railroad interests and other market positions. Their plan relied on keeping President Ulysses S. Grant and the Treasury from releasing government gold.
Grant eventually ordered the Treasury to sell gold. On September 24, 1869, the sudden increase in supply caused gold prices to fall sharply. The resulting turmoil spread through financial markets, damaging speculators and disrupting business. The government sold $4 million in gold, helping break the attempted corner.
Black Friday is sometimes confused with the later retail-shopping term or with the 1929 stock-market dates known as Black Thursday and Black Tuesday. The 1869 episode centered on gold, not a broad collapse in share prices alone.