American Revolution: British forces evacuate Boston, ending the Siege of Boston, after George Washington and Henry Knox place artillery in positions overlooking the city.
Belgium, France, Luxembourg, the Netherlands and the United Kingdom sign the Treaty of Brussels, a precursor to the North Atlantic Treaty establishing NATO.
U.S. President Dwight D. Eisenhower signs the National Security Council directive on the anti-Cuban covert action program that will ultimately lead to the Bay of Pigs Invasion.
Five hundred thirty members of the Ugandan cult Movement for the Restoration of the Ten Commandments of God die in a fire, considered to be a mass murder or suicide orchestrated by leaders of the cult. Elsewhere another 248 members are later found dead.