On October 27, 1787, the first of the Federalist Papers, written by Alexander Hamilton, John Jay, and James Madison under the pen-name "PUBLIUS" to promote the ratification of the new US Constitution, was published in a New York newspaper.

On October 27, 1986, the so-called "Big Bang" deregulated markets throughout the London Stock Exchange as part of Prime Minister Margaret Thatcher's financial reform program.

Learn more about the effects of the Big Bang in the United Kingdom.