August 11
- 3114 BC – The Mesoamerican Long Count calendar, used by several pre-Columbian Mesoamerican civilizations, notably the Mayans, begins.
- 2492 BC – Traditional date of the defeat of Bel by Hayk, progenitor and founder of the Armenian nation.
- 355 – Claudius Silvanus, accused of treason, proclaims himself Roman Emperor against Constantius II.
- 1675 – Franco-Dutch War: Forces of the Holy Roman Empire defeat the French in the Battle of Konzer Brücke.
- 1786 – Captain Francis Light establishes the British colony of Penang in Malaysia.
- 1804 – Francis II assumes the title of first Emperor of Austria.
- 1812 – Peninsular War: French troops engage British-Portuguese forces in the Battle of Majadahonda.
- 1858 – The Eiger in the Bernese Alps is ascended for the first time by Charles Barrington accompanied by Christian Almer and Peter Bohren.
- 1898 – Spanish-American War: American troops enter the city of Mayagüez, Puerto Rico.
- 1918 – World War I: the Battle of Amiens ends.
- 1919 – The constitution of the Weimar Republic is adopted.
- 1920 – The Latvian–Soviet Peace Treaty, which relinquished Russia's authority and pretenses to Latvia, is signed, ending the Latvian War of Independence.
- 1929 – Babe Ruth becomes the first baseball player to hit 500 home runs in his career with a home run at League Park in Cleveland, Ohio.
- 1934 – The first civilian prisoners arrive at the Federal prison on Alcatraz Island.
- 1942 – Actress Hedy Lamarr and composer George Antheil receive a patent for a frequency hopping, spread spectrum communication system that later became the basis for modern technologies in wireless telephones and Wi-Fi.
- 1947 – Muhammad Ali Jinnah, founding father of Pakistan, gives a speech to the Constituent Assembly, the contents and meaning of which remain contentious today.
- 1952 – Hussein bin Talal is proclaimed King of Jordan.
- 1959 – Sheremetyevo International Airport, the second-largest airport in Russia, opens.
- 1960 – Chad declares independence.
- 1961 – The former Portuguese territories in India of Dadra and Nagar Haveli are merged to create the Union Territory Dadra and Nagar Haveli.
- 1965 – Race riots (the Watts riots) begin in the Watts area of Los Angeles, California.
- 1972 – Vietnam War: the last United States ground combat unit departs South Vietnam.
- 1975 – East Timor: Governor Mário Lemos Pires of Portuguese Timor abandons the capital Dili, following a coup by the Timorese Democratic Union (UDT) and the outbreak of civil war between UDT and Fretilin.
- 1982 – A bomb explodes on Pan Am Flight 830, en route from Tokyo to Honolulu, killing one teenager and injuring 15 passengers.
- 1984 – We begin bombing in five minutes United States President Ronald Reagan, while running for re-election, was preparing to make his weekly Saturday address on National Public Radio.
- 1999 – The Salt Lake City Tornado tears through the downtown district of the city, killing one.
- 2003 – NATO takes over command of the peacekeeping force in Afghanistan, marking its first major operation outside Europe in its 54-year-history.
- 2003 – Jemaah Islamiyah leader Riduan Isamuddin, better known as Hambali, is arrested in Bangkok, Thailand.
- 2003 – A heat wave in Paris results in temperatures rising to 112 °F (44 °C), leaving about 144 people dead.[citation needed]
- 2003 – The highest temperature ever seen in Great Britain (38.1 degrees C, 100.6 degrees F) was recorded at Gravesend, Kent.[1]
- 2008 – Sheikh Abdul Aziz is killed by Indian paramilitary forces during a demonstration against the ‘economic blockade’ of the Kashmir Valley.
August 10
- 955 – Battle of Lechfeld: Otto I, Holy Roman Emperor defeats the Magyars, ending 50 years of Magyar invasion of the West.
- 991 – Battle of Maldon: the English, led by Byrhtnoth, Ealdorman of Essex, are defeated by a band of inland-raiding Vikings near Maldon in Essex.
- 1270 – Yekuno Amlak takes the imperial throne of Ethiopia, restoring the Solomonic dynasty to power after a 100-year Zagwe interregnum.
- 1316 – The Second Battle of Athenry takes place near Athenry during the Bruce campaign in Ireland.
- 1519 – Ferdinand Magellan's five ships set sail from Seville to circumnavigate the globe. The Basque second in command Sebastian Elcano will complete the expedition after Magellan's death in the Philippines.
- 1557 – Battle of St. Quentin: Spanish victory over the French in the Habsburg-Valois Wars.
- 1628 – The Swedish warship Vasa sinks in the Stockholm harbour after only about 20 minutes of her maiden voyage.
- 1675 – The foundation stone of the Royal Greenwich Observatory in London is laid.
- 1680 – The Pueblo Revolt begins in New Mexico.
- 1776 – American Revolutionary War: word of the United States Declaration of Independence reaches London.
- 1792 – French Revolution: Storming of the Tuileries Palace – Louis XVI of France is arrested and taken into custody as his Swiss Guards are massacred by the Parisian mob.
- 1793 – The Musée du Louvre is officially opened in Paris, France.
- 1809 – Quito, now the capital of Ecuador, declares independence from Spain. This rebellion will be crushed on August 2, 1810.
- 1813 – Instituto Nacional, is founded by the Chilean patriot José Miguel Carrera. It is Chile's oldest and most prestigious school. Its motto is Labor Omnia Vincit, which means "Work conquers all things".
- 1821 – Missouri is admitted as the 24th U.S. state.
- 1846 – The Smithsonian Institution is chartered by the United States Congress after James Smithson donates $500,000.
- 1861 – American Civil War: Battle of Wilson's Creek – the war enters Missouri when a band of raw Confederate troops defeat Union forces in the southwestern part of the state.
- 1901 – The U.S. Steel Recognition Strike by the Amalgamated Association of Iron and Steel Workers begins.
- 1904 – Russo-Japanese War: the Battle of the Yellow Sea between the Russian and Japanese battleship fleets takes place.
- 1905 – Russo-Japanese War: peace negotiations begin in Portsmouth, New Hampshire.
- 1913 – Second Balkan War: delegates from Bulgaria, Romania, Serbia, Montenegro, and Greece sign the Treaty of Bucharest, ending the war.
- 1920 – World War I: Ottoman sultan Mehmed VI's representatives sign the Treaty of Sèvres that divides up the Ottoman Empire between the Allies.
- 1932 – A 5.1 kilograms (11 lb) chondrite-type meteorite breaks into at least seven pieces and lands near the town of Archie in Cass County, Missouri.
- 1944 – World War II: American forces defeat the last Japanese troops on Guam.
- 1948 – Candid Camera makes its television debut after being on radio for a year as Candid Microphone.
- 1949 – U.S. President Harry S. Truman signs the National Security Act Amendment, streamlining the defense agencies of the United States government, and replacing the Department of War with the United States Department of Defense.
- 1954 – At Massena, New York, the groundbreaking ceremony for the Saint Lawrence Seaway is held.
- 1969 – A day after murdering Sharon Tate and four others, members of Charles Manson's cult kill Leno and Rosemary LaBianca.
- 1971 – The Society for American Baseball Research is founded in Cooperstown, New York.
- 1977 – In Yonkers, New York, 24-year-old postal employee David Berkowitz ("Son of Sam") is arrested for a series of killings in the New York City area over the period of one year.
- 1978 – Three members of the Ulrich family are killed in an accident. This leads to the Ford Pinto litigation.
- 1981 – Murder of Adam Walsh: the head of John Walsh's son is found. This inspires the creation of the television series America's Most Wanted.
- 1988 – Japanese American internment: U.S. President Ronald Reagan signs the Civil Liberties Act of 1988, providing $20,000 payments to Japanese Americans who were either interned in or relocated by the United States during World War II.
- 1990 – The Magellan space probe reaches Venus.
- 1990 – More than 127 Muslims are killed in North East Sri Lanka by paramilitary troops.
- 1993 – An earthquake measuring 7.0 on the Richter Scale hits the South Island of New Zealand.
- 1995 – Oklahoma City bombing: Timothy McVeigh and Terry Nichols are indicted for the bombing. Michael Fortier pleads guilty in a plea-bargain for his testimony.
- 1998 – HRH Prince Al-Muhtadee Billah is proclaimed the crown prince of Brunei with a Royal Proclamation.
- 2003 – The highest temperature ever recorded in the United Kingdom – 38.5 °C (101.3 °F) in Kent. It is the first time the United Kingdom has recorded a temperature over 100 °F (38 °C).
- 2003 – Yuri Malenchenko becomes the first person to marry in space.
- 2006 – Scotland Yard disrupts a major terrorist plot to destroy aircraft traveling from the United Kingdom to the United States.
- 2009 – Twenty people are killed in Handlová, Trenčín Region, in the deadliest mining disaster in Slovakia's history.
August 9
- 48 BC – Caesar's civil war: Battle of Pharsalus – Julius Caesar decisively defeats Pompey at Pharsalus and Pompey flees to Egypt.
- 378 – Gothic War: Battle of Adrianople – A large Roman army led by Emperor Valens is defeated by the Visigoths in present-day Turkey. Valens is killed along with over half of his army.
- 681 – Bulgaria is founded as a Khanate on the south bank of the Danube after defeating the Byzantine armies of Emperor Constantine IV south of the Danube delta.
- 1173 – Construction of the campanile of the cathedral of Pisa (now known as the Leaning Tower of Pisa) begins; it will take two centuries to complete.
- 1329 – Quilon, the first Indian Christian Diocese, is erected by Pope John XXII; the French-born Jordanus is appointed the first Bishop.
- 1483 – Opening of the Sistine Chapel in Rome with the celebration of a Mass.
- 1810 – Napoleon annexes Westphalia as part of the First French Empire.
- 1814 – Indian Wars: the Creek sign the Treaty of Fort Jackson, giving up huge parts of Alabama and Georgia.
- 1842 – The Webster-Ashburton Treaty is signed, establishing the United States-Canada border east of the Rocky Mountains.
- 1854 – Henry David Thoreau published Walden.
- 1862 – American Civil War: Battle of Cedar Mountain – At Cedar Mountain, Virginia, Confederate General Stonewall Jackson narrowly defeats Union forces under General John Pope.
- 1877 – Indian Wars: Battle of Big Hole – A small band of Nez Percé Indians clash with the United States Army.
- 1892 – Thomas Edison receives a patent for a two-way telegraph.
- 1902 – Edward VII and Alexandra of Denmark are crowned King and Queen of the United Kingdom of Great Britain and Ireland.
- 1907 – The first Boy Scout encampment concludes at Brownsea Island in southern England.
- 1925 – A train robbery takes place in Kakori, near Lucknow, India
- 1930 – Betty Boop made her cartoon debut in Dizzy Dishes.
- 1936 – Summer Olympic Games: Games of the XI Olympiad – Jesse Owens wins his fourth gold medal at the games becoming the first American to win four medals in one Olympiad.
- 1942 – Indian leader Mahatma Gandhi is arrested in Bombay by British forces, launching the Quit India Movement.
- 1942 – World War II: Battle of Savo Island – Allied naval forces protecting their amphibious forces during the initial stages of the Battle of Guadalcanal are surprised and defeated by an Imperial Japanese Navy cruiser force.
- 1944 – The United States Forest Service and the Wartime Advertising Council release posters featuring Smokey Bear for the first time.
- 1944 – Continuation war: The Vyborg–Petrozavodsk Offensive, the largest offensive launched by Soviet Union against Finland during the Second World War, ends to a strategic stalemate. Both Finnish and Soviet troops at the Finnish front dug to defensive positions, and the front remains stable until the end of the war.
- 1945 – World War II: Nagasaki is devastated when an atomic bomb, Fat Man, is dropped by the United States B-29 Bockscar. 39,000 people are killed outright.
- 1965 – Singapore is expelled from Malaysia and becomes the first and only country to date to gain independence unwillingly.
- 1965 – A fire at a Titan missile base near Searcy, Arkansas kills 53 construction workers.
- 1969 – Members of a cult led by Charles Manson brutally murder pregnant actress Sharon Tate (wife of Roman Polanski), coffee heiress Abigail Folger, Polish actor Wojciech Frykowski, men's hairstylist Jay Sebring and recent high-school graduate Steven Parent.
- 1971 – The Troubles: The British security forces in Northern Ireland launch Operation Demetrius. Hundreds of people are arrested and interned, thousands are displaced, and twenty are killed in the violence that follows.
- 1974 – As a direct result of the Watergate scandal, Richard Nixon becomes the first President of the United States to resign from office. His Vice President, Gerald Ford, becomes president.
- 1977 – The military-controlled Government of Uruguay announces that it will return the nation to civilian rule through general elections in 1981 for a President and Congress.
- 1988 – Wayne Gretzky is traded from the Edmonton Oilers to the Los Angeles Kings in one of the most controversial player transactions in ice hockey history, upsetting many Canadians so much that some considered him a "traitor" to his home country.
- 1993 – The Liberal Democratic Party of Japan loses a 38-year hold on national leadership.
- 1999 – Russian President Boris Yeltsin fires his Prime Minister, Sergei Stepashin, and for the fourth time fires his entire cabinet.
- 1999 – The Diet of Japan enacts a law establishing the Hinomaru and Kimi Ga Yo as the official national flag and national anthem.
- 2001 – US President George W. Bush announces his support for federal funding of limited research on embryonic stem cells.
- 2006 – At least 21 suspected terrorists were arrested in the 2006 transatlantic aircraft plot that happened in the United Kingdom. The arrests were made in London, Birmingham, and High Wycombe, Buckinghamshire, in an overnight operation.
August 8
- 1220 – Sweden is defeated by Estonian tribes in the Battle of Lihula.
- 1503 – King James IV of Scotland marries Margaret Tudor, daughter of King Henry VII of England at Holyrood Abbey, Edinburgh, Scotland.
- 1576 – The cornerstone for Tycho Brahe's Uraniborg observatory is laid on Hven.
- 1585 – John Davis enters Cumberland Sound in search of the Northwest Passage.
- 1588 – Anglo-Spanish War: Battle of Gravelines – The naval engagement ends, ending the Spanish Armada's attempt to invade England.
- 1605 – The city of Oulu, Finland, is founded by Charles IX of Sweden.
- 1647 – The Irish Confederate Wars and Wars of the Three Kingdoms: Battle of Dungans Hill – English Parliamentary forces defeat Irish forces.
- 1709 – Bartolomeu de Gusmão demonstrates the lifting power of hot air in an audience before the King of Portugal in Lisbon
- 1786 – Mont Blanc on the French – Italian border is climbed for the first time by Jacques Balmat and Dr Michel-Gabriel Paccard.
- 1793 – The insurrection of Lyon occurs during the French Revolution.
- 1794 – Joseph Whidbey leads an expedition to search for the Northwest Passage near Juneau, Alaska.
- 1844 – The Quorum of the Twelve Apostles, headed by Brigham Young, is reaffirmed as the leading body of The Church of Jesus Christ of Latter-day Saints (LDS Church).
- 1863 – American Civil War: following his defeat in the Battle of Gettysburg, General Robert E. Lee sends a letter of resignation to Confederate President Jefferson Davis (which is refused upon receipt).
- 1870 – The Republic of Ploieşti, a failed Radical-Liberal rising against Domnitor Carol of Romania.
- 1876 – Thomas Edison receives a patent for his mimeograph.
- 1908 – Wilbur Wright makes his first flight at a racecourse at Le Mans, France. It is the Wright Brothers' first public flight.
- 1918 – World War I: the Battle of Amiens begins a string of almost continuous victories with a push through the German front lines (Hundred Days Offensive).
- 1929 – The German airship Graf Zeppelin begins a round-the-world flight.
- 1940 – The "Aufbau Ost" directive is signed by Wilhelm Keitel.
- 1945 – World War II: The Soviet Union declares war on Japan and begins the Manchurian Strategic Offensive Operation.
- 1946 – First flight of the Convair B-36, the world's first mass-produce nuclear weapon delivery vehicle.
- 1960 – South Kasai secedes from the Congo.
- 1963 – Great Train Robbery: in England, a gang of 15 train robbers steal 2.6 million pounds in bank notes.
- 1967 – The Association of Southeast Asian Nations (ASEAN) is founded by Indonesia, Malaysia, the Philippines, Singapore and Thailand.
- 1973 – Kim Dae-Jung, a South Korean politician and later president of South Korea, is kidnapped.
- 1974 – Watergate scandal: U.S. President Richard Nixon announces his resignation, effective the next day.
- 1980 – The Central Hotel Fire occurs in Bundoran, Ireland.
- 1988 – The "8888 Uprising" occurs in Burma.
- 1989 – Space Shuttle program: STS-28 Mission – Space Shuttle Columbia takes off on a secret five-day military mission.
- 1990 – Iraq occupies Kuwait and the state is annexed to Iraq. This would lead to the Gulf War shortly afterward.
- 1991 – The Warsaw radio mast, at one time the tallest construction ever built, collapses.
- 2000 – Confederate submarine H.L. Hunley is raised to the surface after 136 years on the ocean floor and 30 years after its discovery by undersea explorer E. Lee Spence and 5 years after being filmed by a dive team funded by novelist Clive Cussler.
- 2007 – An EF2 tornado touches down in Kings County and Richmond County, New York State, the most powerful tornado in New York to date and the first in Brooklyn since 1889.
August 7
- 322 BC – Battle of Crannon between Athens and Macedon.
- 461 – Roman Emperor Majorian is beheaded near the river Iria in north-west Italy.
- 626 – The Avar and Slav armies leave the siege of Constantinople.
- 936 – Coronation of King Otto I of Germany.
- 1420 – Construction of the dome of Santa Maria del Fiore begins in Florence.
- 1427 – The Visconti of Milan's fleet is destroyed by the Venetians on the Po River.
- 1461 – The Ming Dynasty Chinese military general Cao Qin stages a coup against the Tianshun Emperor.
- 1679 – The brigantine Le Griffon, commissioned by René Robert Cavelier, Sieur de La Salle, is towed to the south-eastern end of the Niagara River, to become the first ship to sail the upper Great Lakes of North America.
- 1714 – The Battle of Gangut: the first important victory of the Russian Navy.
- 1782 – George Washington orders the creation of the Badge of Military Merit to honor soldiers wounded in battle. It is later renamed to the more poetic Purple Heart.
- 1789 – The United States War Department is established.
- 1791 – United States troops destroy the Miami town of Kenapacomaqua near the site of present-day Logansport, Indiana in the Northwest Indian War.
- 1794 – U.S. President George Washington invokes the Militia Law of 1792 to suppress the Whiskey Rebellion in western Pennsylvania.
- 1819 – Simón Bolívar triumphs over Spain in the Battle of Boyacá.
- 1879 – The opening of the Poor Man's Palace in Manchester.
- 1890 – Anna Månsdotter becomes the last woman in Sweden to be executed, for the 1889 Yngsjö murder.
- 1909 – Alice Huyler Ramsey and three friends become the first women to complete a transcontinental auto trip, taking 59 days to travel from New York City to San Francisco.
- 1927 – The Peace Bridge opens between Fort Erie, Ontario and Buffalo, New York.
- 1930 – The last confirmed lynching of blacks in the Northern United States occurs in Marion, Indiana. Two men, Thomas Shipp and Abram Smith, are killed.
- 1933 – The Simele massacre: The Iraqi Government slaughters over 3,000 Assyrians in the village of Sumail. The day becomes known as Assyrian Martyrs Day.
- 1940 – World War II: Alsace Lorraine is annexed by the Third Reich.
- 1942 – World War II: the Battle of Guadalcanal begins – United States Marines initiate the first American offensive of the war with landings on Guadalcanal and Tulagi in the Solomon Islands.
- 1944 – IBM dedicates the first program-controlled calculator, the Automatic Sequence Controlled Calculator (known best as the Harvard Mark I).
- 1947 – Thor Heyerdahl's balsa wood raft the Kon-Tiki, smashes into the reef at Raroia in the Tuamotu Islands after a 101-day, 7,000 kilometres (4,300 mi) journey across the Pacific Ocean in an attempt to prove that pre-historic peoples could have traveled from South America.
- 1947 – The Bombay Municipal Corporation formally takes over the Bombay Electric Supply and Transport (BEST).
- 1955 – Tokyo Telecommunications Engineering, the precursor to Sony, sells its first transistor radios in Japan.
- 1959 – The Lincoln Memorial design on the U.S. penny goes into circulation. It replaces the "sheaves of wheat" design, and was minted until 2008.
- 1959 – Explorer program: Explorer 6 launches from the Atlantic Missile Range in Cape Canaveral, Florida.
- 1960 – Côte d'Ivoire becomes independent.
- 1964 – Vietnam War: the U.S. Congress passes the Gulf of Tonkin Resolution giving US President Lyndon B. Johnson broad war powers to deal with North Vietnamese attacks on American forces.
- 1964 – Prometheus, a bristlecone pine and the world's oldest tree, is cut down.
- 1965 – The infamous first party between Ken Kesey's Merry Pranksters and motorcycle gang the Hells Angels takes place at Kesey's estate in La Honda, California introducing psychedelics to the gang world and forever linking the hippie movement to the Hell's Angels.
- 1966 – Race riots occur in Lansing, Michigan.
- 1967 – Vietnam War: the People's Republic of China agrees to give North Vietnam an undisclosed amount of aid in the form of a grant.
- 1970 – California judge Harold Haley is taken hostage in his courtroom and killed during in an effort to free George Jackson from police custody.
- 1974 – Philippe Petit performs a high wire act between the twin towers of the World Trade Center 1,368 feet (417 m) in the air.
- 1976 – Viking program: Viking 2 enters orbit around Mars.
- 1978 – U.S. President Jimmy Carter declares a federal emergency at Love Canal.[why?]
- 1979 – Several tornadoes struck the city of Woodstock, Ontario, Canada and the surrounding communities.
- 1981 – The Washington Star ceases all operations after 128 years of publication.
- 1985 – Takao Doi, Mamoru Mohri and Chiaki Mukai are chosen to be Japan's first astronauts.
- 1988 – Rioting in New York City's Tompkins Square Park.
- 1989 – U.S. Congressman Mickey Leland (D-TX) and 15 others die in a plane crash in Ethiopia.
- 1998 – The United States embassy bombings in Dar es Salaam, Tanzania and Nairobi, Kenya kill approximately 212 people.
- 2007 – Barry Bonds of the San Francisco Giants breaks* baseball great Hank Aaron's record by hitting his 756th home run.
- 2008 – Georgia launches a military offensive against South Ossetia to counter the alleged Russian invasion, starting the South Ossetia War.
August 6
- 1284 – The Republic of Pisa is defeated in the Battle of Meloria by the Republic of Genoa, thus losing its naval dominance in the Mediterranean.
- 1506 – The Grand Duchy of Lithuania defeated the Crimean Khanate in the Battle of Kletsk
- 1538 – Bogotá, Colombia, is founded by Gonzalo Jiménez de Quesada.
- 1661 – The Treaty of The Hague is signed by Portugal and the Dutch Republic.
- 1787 – Sixty proof sheets of the Constitution of the United States are delivered to the Constitutional Convention in Philadelphia.
- 1806 – Francis II, the last Holy Roman Emperor, abdicates ending the Holy Roman Empire.
- 1819 – Norwich University is founded in Vermont as the first private military school in the United States.
- 1825 – Bolivia gains independence from Spain.
- 1845 – The Russian Geographical Society is founded in Saint Petersburg.
- 1861 – The United Kingdom annexes Lagos, Nigeria.
- 1862 – American Civil War: the Confederate ironclad CSS Arkansas is scuttled on the Mississippi River after suffering damage in a battle with USS Essex near Baton Rouge, Louisiana.
- 1870 – Franco-Prussian War: the Battle of Wörth results in a decisive Prussian victory.
- 1890 – At Auburn Prison in New York, murderer William Kemmler becomes the first person to be executed by electric chair.
- 1901 – Kiowa land in Oklahoma is opened for white settlement, effectively dissolving the contiguous reservation.
- 1912 – The Bull Moose Party meets at the Chicago Coliseum.
- 1914 – World War I: First Battle of the Atlantic – two days after the United Kingdom had declared war on Germany over the German invasion of Belgium, ten German U-boats leave their base in Helgoland to attack Royal Navy warships in the North Sea.
- 1914 – World War I: Serbia declares war on Germany; Austria declares war on Russia.
- 1915 – World War I: Battle of Sari Bair – the Allies mount a diversionary attack timed to coincide with a major Allied landing of reinforcements at Suvla Bay.
- 1917 – World War I: Battle of Mărăşeşti between the Romanian and German armies begins.
- 1926 – Gertrude Ederle becomes the first woman to swim across the English Channel.
- 1926 – In New York City, the Warner Brothers' Vitaphone system premieres with the movie Don Juan starring John Barrymore.
- 1926 – Harry Houdini performs his greatest feat, spending 91 minutes underwater in a sealed tank before escaping.
- 1930 – Judge Joseph Force Crater steps into a taxi in New York and disappears to be never seen again.
- 1940 – Estonia was illegaly annexed by the Soviet Union.
- 1942 – Queen Wilhelmina of the Netherlands becomes the first reigning queen to address a joint session of the United States Congress.
- 1945 – World War II: Hiroshima is devastated when the atomic bomb "Little Boy" is dropped by the United States B-29 Enola Gay. Around 70,000 people are killed instantly, and some tens of thousands die in subsequent years from burns and radiation poisoning.
- 1956 – After going bankrupt in 1955, the American broadcaster DuMont Television Network makes its final broadcast, a boxing match from St. Nicholas Arena in New York in the Boxing from St. Nicholas Arena series.
- 1960 – Cuban Revolution: in response to a United States embargo, Cuba nationalizes American and foreign-owned property in the nation.
- 1962 – Jamaica becomes independent from the United Kingdom.
- 1964 – Prometheus, a bristlecone pine and the world's oldest tree, is cut down.
- 1965 – US President Lyndon B. Johnson signs the Voting Rights Act of 1965 into law.
- 1966 – Braniff Airlines Flight 250 crashes in Falls City, NE killing all 42 on board.
- 1976 – Zulfikar Ali Bhutto lays the foundation stone of Port Qasim, Karachi.
- 1986 – A low-pressure system that redeveloped off the New South Wales coast dumps a record 328 millimeters (13 inches) of rain in a day on Sydney.
- 1988 – The Tompkins Square Park Police Riot in New York City spurs a reform of the NYPD, held responsible for the event.
- 1990 – Gulf War: the United Nations Security Council orders a global trade embargo against Iraq in response to Iraq's invasion of Kuwait.
- 1991 – Tim Berners-Lee releases files describing his idea for the World Wide Web. WWW debuts as a publicly available service on the Internet.
- 1991 – Doi Takako, chair of the Social Democratic Party, becomes Japan's first female speaker of the House of Representatives.
- 1993 – Heavy rains and debris kill 72 in the Kagoshima and Aira areas of Kyūshū, Japan.
- 1996 – NASA announces that the ALH 84001 meteorite, thought to originate from Mars, contains evidence of primitive life-forms.
- 1997 – Korean Air Flight 801, a Boeing 747-300, crashes into the jungle on Guam on approach to airport, killing 228.
- 2008 – A military junta led by Mohamed Ould Abdel Aziz stages a coup d'état in Mauritania, overthrowing president Sidi Ould Cheikh Abdallahi.
- 2010 – The incoming coalition government of the United Kingdom discontinues the use of the controversial ContactPoint database of children.
