September 6 is the 249th day of the year (250th in leap years). There are 116 days remaining.
- 3761 BC – The first day of the Hebrew Calendar.
- 394 – Battle of Frigidus: The Christian Roman Emperor Theodosius I defeats and kills the pagan usurper Eugenius and his Frankish general Arbogast.
- 1522 – The Victoria, one of the surviving ships of Ferdinand Magellan's expedition, returns to San Lucar de Barrameda in Spain, becoming the first ship to circumnavigate the world.
- 1620 – The Pilgrims sail from Plymouth, England, on the Mayflower to settle in North America.
- 1628 – Puritans settle Salem which will later become part of Massachusetts Bay Colony.
- 1781 – The Battle of Groton Heights takes place with the result of a British minor victory
- 1847 – Henry David Thoreau leaves Walden Pond and moves in with Ralph Waldo Emerson and his family in Concord, Massachusetts.
- 1861 – American Civil War: Forces under Union General Ulysses S. Grant bloodlessly capture Paducah, Kentucky, which gives the Union control the mouth of the Tennessee River.
- 1863 – American Civil War: Confederates evacuate Battery Wagner and Morris Island in South Carolina.
- 1870 – Louisa Ann Swain of Laramie, Wyoming, votes in the morning, becoming the first woman in the United States to cast a vote legally after 1807.
- 1885 – Eastern Rumelia declares its union with Bulgaria.
- 1888 – Charles Turner becomes the first bowler to take 250 wickets in an English season – a feat since accomplished only by Tom Richardson (twice), J.T. Hearne, Wilfred Rhodes (twice) and Tich Freeman (six times).
- 1901 – American anarchist Leon Czolgosz shoots and fatally wounds US President William McKinley at the Pan-American Exposition in Buffalo, New York.
- 1915 – The first prototype tank is tested for the British Army for the first time.
- 1936 – The last surviving member of the thylacine species, Benjamin, dies alone in his cage at the Hobart Zoo in Tasmania.
- 1937 – Spanish Civil War: The start of the Battle of El Mazuco.
- 1939 – World War II: South Africa declares war on Germany.
- 1941 – Holocaust: The requirement to wear the Star of David with the word Jew inscribed, is extended to all Jews over the age of 6 in German-occupied areas.
- 1948 – Juliana becomes Queen of the Netherlands.
- 1949 – Allied military authorities relinquish control of former Nazi Germany assets back to German control.
- 1965 – War of 1965: India attacks Pakistan and announces that its forces will capture Lahore (city of Pakistan) in an hour.
- 1966 – In Cape Town, the South African architect of Apartheid, Prime Minister Hendrik Verwoerd is stabbed to death during a parliamentary meeting.
- 1968 – Swaziland becomes independent.
- 1970 – Four passenger jets are simultaneously hijacked. Two are taken to Dawson's Field.
- 1972 – Munich Massacre: Israeli athletes and coaches are killed when police assault Black September members in a failed hostage rescue in West Germany.
- 1976 – Cold War: Soviet air force pilot Lt. Viktor Belenko lands a MiG-25 jet fighter at Hakodate on the island of Hokkaido in Japan and requests political asylum from the United States.
- 1983 – The Soviet Union admits to shooting down Korean Air Flight KAL-007, stating that the pilots did not know it was a civilian aircraft when it violated Soviet airspace.
- 1985 – Midwest Express Airlines Flight 105, a Douglas DC-9 crashes just after takeoff from Milwaukee, Wisconsin, killing 31.
- 1986 – In Istanbul, two Arab terrorists from Abu Nidal's terror organization kill 22 and wound six inside the Neve Shalom synagogue during Shabbat services.
- 1991 – The Soviet Union recognizes the independence of the Baltic states: Estonia, Latvia and Lithuania.
- 1991 – The name Saint Petersburg is restored to Russia's second largest city, which had been renamed Leningrad in 1924.
- 1995 – With the jury absent, Los Angeles police detective Mark Fuhrman invokes his Fifth Amendment right against self-incrimination in the murder trial of O. J. Simpson.
- 1995 – Cal Ripken Jr. breaks Lou Gehrig's record of playing 2131 consecutive baseball games.
- 1997 – The funeral of Diana, Princess of Wales at Westminster Abbey draws large crowds.
- 2000 – In New York City, the United Nations Millennium Summit begins with more than 180 world leaders present.
- 2001 – United States v. Microsoft: The United States Justice Department announces that it was no longer seeking to break-up software maker Microsoft and will instead seek a lesser antitrust penalty.
- 1620 – Isabella Leonarda, composer
- 1757 – Marquis de Lafayette, French soldier (d. 1834)
- 1766 – John Dalton, British chemist and physicist (d. 1844)
- 1781 – Anton Diabelli, Austrian music publisher and composer (d. 1858)
- 1795 – Frances Wright, writer, activist, and lecturer (d. 1852)
- 1800 – Catharine Beecher, educator (d. 1878)
- 1829 – Marie Zakrzewska, physician
- 1839 – Louise-Lëonie Rouzade, writer
- 1857 – Zelia Nuttall, archeologist and historian
- 1859 – Boris Yakovlovic Bukreev, Russian mathematician (d. 1962)
- 1860 – Jane Addams, social worker (d. 1935)
- 1868 – Margaret Dreier Robins, labor leader and reformer
- 1869 – Felix Salten, author (d. 1945)
- 1877 – Buddy Bolden, American jazz musician (d. 1930)
- 1888 – Joseph P. Kennedy, Sr., American politician (d. 1969)
- 1890 – Claire Chennault, soldier (d. 1958)
- 1892 – Sir Edward Appleton, English physicist, winner of the Nobel Prize in Physics
- 1899 – Billy Rose, composer (d. 1966)
- 1900 – W.A.C. Bennett, Canadian politician (d. 1979)
- 1901 – Ernst Weber, physicist
- 1904 – Slapsie Maxie Rosenbloom, boxer (d. 1976)
- 1911 – Harry Danning, Major League Baseball player (d. 2004)
- 1928 – Robert M. Pirsig, author
- 1929 – Yash Johar, Indian film producer
- 1937 – Jo Anne Worley, actress
- 1937 – Sergio Aragonés, illustrator
- 1937 – Brigid Berlin, actor and artist
- 1944 – Roger Waters, musician (Pink Floyd)
- 1944 – Swoosie Kurtz, actress
- 1947 – Jane Curtin, actress
- 1958 – Jeff Foxworthy, comedian, actor, and author
- 1964 – Rosie Perez, actress
- 1969 – Ce Ce Peniston, American singer
- 1970 – Paul Miller, (DJ Spooky) American composer, artist, author
- 1971 – Dolores O'Riordan, musician (The Cranberries)
- 1972 – China Miéville, writer
- 1973 – Greg Rusedski, tennis player
- 1974 – Justin Whalin, actor
- 1974 – Tim Henman, tennis player
- 1979 – Foxy Brown, rapper
- 972 – Pope John XIII
- 1511 – Ashikaga Yoshizumi, Ashikaga shogun (b. 1481)
- 1683 – Jean-Baptiste Colbert, French minister of finance
- 1708 – Sir John Morden, philanthropist (b. 1623)
- 1782 – Martha Wayles Skelton Jefferson, wife of Thomas Jefferson (b. 1748)
- 1902 – Frederick Augustus Abel, British chemist
- 1951 – Joan Vollmer, wife of William S. Burroughs
- 1952 – Gertrude Lawrence, actress
- 1962 – Hanns Eisler, composer
- 1966 – Hendrik Verwoerd, South African prime minister
- 1966 – Margaret Sanger, birth control activist
- 1984 – Ernest Tubb, country music singer
- 1990 – Len Hutton, English cricketer (b. 1916)
- 1994 – Nicky Hopkins, British musician (b. February 24, 1944)
- 1998 – Akira Kurosawa, Japanese film director
Holidays and observances
September 5 – September 7 – August 6 – October 6 – Historical anniversaries