20 September 1873: The NYSE closes in the Panic of 1873

Two days after the failure of Jay Cooke and Company, a major bank heavily invested in railroad bonds, panic swept Wall Street. The New York Stock Exchange closed its doors for the first time in its history, staying shut for ten days. The panic set off a long depression in the US and Europe. Too much borrowed money had been poured into railroads that could not pay it back.

The lesson: Speculative overbuilding financed with debt tends to end in painful busts that last for years.