1984 – "We begin bombing in five minutes": United States President Ronald Reagan, while running for re-election, jokes while preparing to make his weekly Saturday address on National Public Radio.

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, two-way radio communications, and Wi-Fi.

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.

1974 – As a direct result of the Watergate scandal, Richard Nixon becomes the first President of the United States to resign from office. Vice President Gerald Ford becomes president.

1945 – World War II: Nagasaki is devastated when an atomic bomb, Fat Man, is dropped by the United States B-29 Bockscar. Thirty-five thousand people are killed outright, including 23,200–28,200 Japanese war workers, 2,000 Korean forced workers, and 150 Japanese soldiers.

1944 – The United States Forest Service and the Wartime Advertising Council release posters featuring Smokey Bear for the first time.

1854 – American Transcendentalist philosopher Henry David Thoreau publishes his memoir Walden.

2022 – The Federal Bureau of Investigation (FBI) executes a search warrant at former president Donald Trump's residence in Mar-a-Lago, Palm Beach, Florida.

1974 – President Richard Nixon, in a nationwide television address, announces his resignation from the office of the President of the United States effective noon the next day.

1969 – At a zebra crossing in London, photographer Iain Macmillan takes the iconic photo that becomes the cover image of the Beatles' album Abbey Road.

1576 – The cornerstone for Tycho Brahe's Uraniborg observatory is laid on the island of Hven.

1944 – IBM dedicates the first program-controlled calculator, the Automatic Sequence Controlled Calculator (known best as the Harvard Mark I).

2012 – NASA's Curiosity rover lands on the surface of Mars.

1996 – NASA announces that the ALH 84001 meteorite, thought to originate from Mars, contains evidence of primitive life-forms.

1991 – Tim Berners-Lee releases files describing his idea for the World Wide Web. WWW makes its first appearance as a publicly available service on the Internet.

1945 – World War II: Hiroshima, Japan 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.

1974 – Watergate scandal: President Richard Nixon, under orders of the US Supreme Court, releases the "Smoking Gun" tape, recorded on June 23, 1972, clearly revealing his actions in covering up and interfering investigations into the break-in. His political support vanishes completely.

1962 – Apartheid: Nelson Mandela is jailed. He would not be released until 1990.

1957 – American Bandstand, a show dedicated to the teenage "baby-boomers" by playing the songs and showing popular dances of the time, debuts on the ABC television network.

1944 – The Holocaust: A tip from a Dutch informer leads the Gestapo to a sealed-off area in an Amsterdam warehouse, where they find and arrest Jewish diarist Anne Frank, her family, and four others.