On September 1, 1939, World War II began as Nazi Germany invaded Poland.

On September 2, 1945, Japan formally surrendered in ceremonies aboard the USS Missouri, ending World War II.

On September 3, 1976, the unmanned U.S. spacecraft Viking 2 landed on Mars to take the first close-up, color photographs of the planet's surface.

On September 4, 1957, Arkansas Gov. Orval Faubus called out the National Guard to prevent nine black students from entering Central High School in Little Rock.

On September 5, 1972, Arab guerrillas attacked the Israeli delegation at the Munich Olympic games; 11 Israelis, five guerrillas and a police officer were killed in the siege.

On September 6, 1901, President McKinley was shot and mortally wounded by anarchist Leon Czolgosz at the Pan-American Exposition in Buffalo, N.Y.

On September 7, 1940, Nazi Germany began its initial blitz on London during World War II.

On September 8,1974, President Ford granted an unconditional pardon to former President Nixon.

On September 9, 1976, Communist Chinese leader Mao Tse-tung died in Beijing at age 82.

On September 10, 1919, New York City welcomed home Gen. John J. Pershing and 25,000 soldiers who had served in the U.S. First Division during World War I.

On September 11, 1973, Chilean President Salvador Allende died in a violent military coup.

On September 12,1977, South African black student leader Steven Biko died while in police custody, triggering an international outcry.

On September 13,1993, at the White House, Israeli Prime Minister Yitzhak Rabin and PLO chairman Yasser Arafat shook hands after signing an accord granting limited Palestinian autonomy.

On September 14, 1959, the Soviet space probe Luna 2 became the first man-made object to reach the moon as it crashed onto the lunar surface.

On September 15,1963, four children were killed when a bomb went off during Sunday services at a black Baptist church in Birmingham, Alabama.

On September 16,1974, President Ford announced a conditional amnesty program for Vietnam War deserters and draft-evaders.

On September 17,1862, Union forces hurled back a Confederate invasion of Maryland in the Civil War Battle of Antietam. During the battle, 23,100 were killed, wounded or captured, making it the bloodiest day in U.S. military history.

On September 18,1947, the National Security Act, which unified the Army, Navy and newly formed Air Force into a National Military Establishment, went into effect.

On September 19, 1881, the 20th president of the United States, James A. Garfield, died of wounds inflicted by an assassin.

On September 20, 1973, Billie Jean King defeated Bobby Riggs in straight sets 6-4, 6-3, 6-3 in a $100,000 winner-take-all tennis match.

On September 21,1938, a hurricane struck parts of New York and New England, causing widespread damage and claiming more than 600 lives.

On September 22, 1862, President Lincoln issued the preliminary Emancipation Proclamation, declaring all slaves in rebel states should be free as of Jan. 1, 1863.

On September 23, 1952, Republican vice-presidential candidate Richard M. Nixon went on television to deliver what came to be known as the ``Checkers'' speech as he refuted allegations of improper campaign financing.

On September 24, 1996, the United States, represented by President Clinton, and the world's other major nuclear powers signed a treaty to end all testing and development of nuclear weapons.

On September 25, 1957, with 300 U.S. Army troops standing guard, nine black children forced to withdraw from Central High School in Little Rock, Ark. because of unruly white crowds, were escorted to class.

On September 26,1960, the first televised debate between presidential candidates Richard M. Nixon and John F. Kennedy took place in Chicago.

On September 27,1964, the Warren Commission issued a report concluding that Lee Harvey Oswald had acted alone in assassinating President Kennedy.

On September 28,1924, two U.S. Army planes landed in Seattle, Wash., having completed the first round-the-world flight in 175 days.

On September 29, 1957, the New York Giants played their last game at the Polo Grounds, losing to the Pittsburgh Pirates 9-1. The Giants moved to San Francisco for the next season.

On September 30, 1938, British, French, German,and Italian leaders decided to appease Adolf Hitler by allowing Nazi annexation of Czechoslovakia's Sudetenland.