In a referendum, Estonia approves joining the European Union.

Historic National Prayer Service held at Washington National Cathedral for victims of the September 11 attacks. A similar service is held in Canada on Parliament Hill, the largest vigil ever held in the nation's capital.

Kiribati, Nauru and Tonga join the United Nations.

Telecommunications companies MCI Communications and WorldCom complete their $37 billion merger to form MCI WorldCom.

Body Worlds opens in Tokyo, Japan

The Major League Baseball season is canceled because of a strike.

The Toronto Blue Jays set a record for the most home runs in a single game, hitting 10 of them.

Joe Kittinger becomes the first person to fly a hot air balloon alone across the Atlantic Ocean.

President-elect of Lebanon, Bachir Gemayel, is assassinated.

The first American saint, Elizabeth Ann Seton, is canonized by Pope Paul VI.

The US Selective Service selects September 14th as the First Draft Lottery Date.

The Organization of the Petroleum Exporting Countries (OPEC) is founded.

The Soviet probe ''Luna 2'' crashes onto the Moon, becoming the first man-made object to reach it.

The first two German post-war rockets, designed by the German engineer Ernst Mohr, reach the upper atmosphere.

Groundbreaking for the United Nations headquarters in New York City.

World War II: Maastricht becomes the first Dutch city to be liberated by allied forces.

Miguel Primo de Rivera becomes dictator of Spain.

Russia is officially proclaimed a republic.

President of the United States William McKinley dies after an assassination attempt on September 6, and is succeeded by Theodore Roosevelt.

American Civil War: The Battle of South Mountain, part of the Maryland Campaign, is fought.

Mexican-American War: Winfield Scott captures Mexico City.

The Ottoman Empire signs the Treaty of Adrianople with Russia, thus ending the Russo-Turkish War.

The poem ''Defence of Fort McHenry'' is written by Francis Scott Key. The poem is later used as the lyrics of The Star-Spangled Banner.

Napoleonic Wars: French grenadiers enter Moscow. The Fire of Moscow begins as soon as Russian troops leave the city.

The British Empire adopts the Gregorian calendar, skipping eleven days (the previous day was September 2).

George Frideric Handel completes his oratorio ''Messiah''

Bishop Gore School, one of the oldest schools in Wales, is founded.

Flight of the Earls from Lough Swilly, Donegal, Ireland.

Battle of Ishibashiyama in Japan.

Harun al-Rashid becomes the Abbasid caliph upon the death of his brother al-Hadi.

Domitian becomes Emperor of the Roman Empire upon the death of his brother Titus.