1778 - The United States signed its first treaty with a Native American tribe, the Delaware Nation.
1787 - The Constitution of the United States of America was signed by delegates at the Constitutional Convention.
1930 - Construction on Boulder Dam, later renamed Hoover Dam, began in Black Canyon, near Las Vegas, NV.
1932 - Sir Malcolm Campbell set a speed record when he reached 276.27 mph over a half mile.
1939 - The Soviet Union invaded Poland. Germany had invaded Poland on September 1.
1944 - Operation "Market Garden" was launched by Allied paratroopers during World War II. The landing point was behind German lines in the Netherlands.
1962 - U.S. space officials announced the selection of Neil A. Armstrong and eight others as new astronauts.
1995 - Hong Kong held its last legislative election before being taken over by China in 1997.
1997 - Northern Ireland's main Protestant party joined in peace talks. It was the first time that all of the major players had come together.