| 100051 | September 3 | Event | 1798 – The week long battle of St. George's Caye begins between Spain and Britain off the coast of Belize. |
| 100052 | September 3 | Event | 1802 – William Wordsworth composes the sonnet Composed upon Westminster Bridge, September 3, 1802. |
| 100053 | September 3 | Event | 1812 – Twenty-four settlers are killed in the Pigeon Roost Massacre in Indiana. |
| 100054 | September 3 | Event | 1838 – Future abolitionist Frederick Douglass escapes from slavery. |
| 100055 | September 3 | Event | 1843 – King Otto of Greece is forced to grant a constitution following an uprising in Athens. |
| 100056 | September 3 | Event | 1855 – American Indian Wars: In Nebraska, 700 soldiers under United States General William S. Harney avenge the Grattan massacre by attacking a Sioux village and killing 100 men, women and children. |
| 100057 | September 3 | Event | 1861 – American Civil War: Confederate General Leonidas Polk invades neutral Kentucky, prompting the state legislature to ask for Union assistance. |
| 100058 | September 3 | Event | 1870 – Franco-Prussian War: The Siege of Metz begins, resulting in a decisive Prussian victory on October 23. |
| 100059 | September 3 | Event | 1874 – The congress of the State of Mexico elevates Naucalpan to the category of villa, with the title of "Villa de Juárez". |
| 100060 | September 3 | Event | 1875 – The first official game of polo is played in Argentina after being introduced by British ranchers. |
| 100061 | September 3 | Event | 1878 – Over 640 die when the crowded pleasure boat Princess Alice collides with the Bywell Castle in the River Thames. |
| 100062 | September 3 | Event | 1879 – Siege of the British Residency in Kabul: British envoy Sir Louis Cavagnari and 72 men of the The Guides are massacred by Afghan troops while defending the British Residency in Kabul. Their heroism and loyalty became famous and revered throughout th |
| 100063 | September 3 | Event | 1895 – John Brallier becomes the first openly professional American football player, when he was paid US$10 by David Berry, to play for the Latrobe Athletic Association in a 12–0 win over the Jeanette Athletic Association. |
| 100064 | September 3 | Event | 1914 – William, Prince of Albania leaves the country after just six months due to opposition to his rule. |
| 100065 | September 3 | Event | 1914 – French composer Albéric Magnard is killed defending his estate against invading German soldiers. |
| 100066 | September 3 | Event | 1914 – World War I: Start of the Battle of Grand Couronné, a German assault against French positions on high ground near the city of Nancy. |
| 100067 | September 3 | Event | 1916 – World War I: Leefe Robinson destroys the German airship Schütte-Lanz SL 11 over Cuffley, north of London the first German airship to be shot down on British soil. |
| 100068 | September 3 | Event | 1925 – USS Shenandoah, the United States' first American-built rigid airship, was destroyed in a squall line over Noble County, Ohio. Fourteen of her 42-man crew perished, including her commander, Zachary Lansdowne. |
| 100069 | September 3 | Event | 1933 – Yevgeniy Abalakov is the first man to reach the highest point in the Soviet Union, Communism Peak (now called Ismoil Somoni Peak and situated in Tajikistan) (7495 m). |
| 100070 | September 3 | Event | 1935 – Sir Malcolm Campbell reaches a speed of 304.331 miles per hour on the Bonneville Salt Flats in Utah, becoming the first person to drive an automobile over 300 mph. |
| 100071 | September 3 | Event | 1939 – World War II: France, the United Kingdom, New Zealand and Australia declare war on Germany after the invasion of Poland, forming the Allies. |
| 100072 | September 3 | Event | 1939 – World War II: The United Kingdom and France begin a naval blockade of Germany that lasts until the end of the war. This also marks the beginning of the Battle of the Atlantic. |
| 100073 | September 3 | Event | 1941 – The Holocaust: Karl Fritzsch, deputy camp commandant of the Auschwitz concentration camp, experiments with the use of Zyklon B in the gassing of Soviet POWs. |
| 100074 | September 3 | Event | 1942 – World War II: In response to news of its coming liquidation, Dov Lopatyn leads an uprising in the Ghetto of Lakhva, in present-day Belarus. |
| 100075 | September 3 | Event | 1943 – World War II: The Allied invasion of Italy begins on the same day that U.S. General Dwight D. Eisenhower and Italian Marshal Pietro Badoglio sign the Armistice of Cassibile aboard the Royal Navy battleship HMS Nelson off Malta. |
| 100076 | September 3 | Event | 1944 – Holocaust: Diarist Anne Frank and her family are placed on the last transport train from the Westerbork transit camp to the Auschwitz concentration camp, arriving three days later. |
| 100077 | September 3 | Event | 1945 – A three-day celebration begins in China, following the Victory over Japan Day on September 2. |
| 100078 | September 3 | Event | 1950 – "Nino" Farina becomes the first Formula One Drivers' champion after winning the 1950 Italian Grand Prix. |
| 100079 | September 3 | Event | 1951 – The first long-running American television soap opera, Search for Tomorrow, airs its first episode on the CBS network. |
| 100080 | September 3 | Event | 1954 – The People's Liberation Army begins shelling the Republic of China-controlled islands of Quemoy, starting the First Taiwan Strait Crisis. |