1983 – First publications of the discovery of the HIV virus that causes AIDS in the journal Science by a team of French scientists including Françoise Barré-Sinoussi, Jean-Claude Chermann, and Luc Montagnier.

1964 – Discovery of the cosmic microwave background radiation by Robert Woodrow Wilson and Arno Penzias.

1873 – Levi Strauss and Jacob Davis receive a U.S. patent for blue jeans with copper rivets.

1609 – Shakespeare's sonnets are first published in London, perhaps illicitly, by the publisher Thomas Thorpe.

1570 – Cartographer Abraham Ortelius issues Theatrum Orbis Terrarum, the first modern atlas.

1974 – Nuclear weapons testing: Under project Smiling Buddha, India successfully detonates its first nuclear weapon becoming the sixth nation to do so.

1896 – The United States Supreme Court rules in Plessy v. Ferguson that the "separate but equal" doctrine is constitutional.

2004 – The first legal same-sex marriages in the U.S. are performed in the state of Massachusetts.

1990 – The General Assembly of the World Health Organization (WHO) eliminates homosexuality from the list of psychiatric diseases.

1954 – The United States Supreme Court hands down a unanimous decision in Brown v. Board of Education of Topeka, Kansas, outlawing racial segregation in public schools.

1902 – Greek archaeologist Valerios Stais discovers the Antikythera mechanism, an ancient mechanical analog computer.

1960 – Theodore Maiman operates the first optical laser (a ruby laser), at Hughes Research Laboratories in Malibu, California.

1888 – Nikola Tesla delivers a lecture describing the equipment which will allow efficient generation and use of alternating currents to transmit electric power over long distances.

1957 – At Malden Island in the Pacific Ocean, Britain tests its first hydrogen bomb in Operation Grapple.

1973 – Skylab, the United States' first space station, is launched.

1961 – Civil rights movement: A white mob twice attacks a Freedom Riders bus near Anniston, Alabama, before fire-bombing the bus and attacking the civil rights protesters who flee the burning vehicle.

1939 – Lina Medina becomes the youngest confirmed mother in medical history at the age of five.

1796 – Edward Jenner administers the first smallpox inoculation.

1985 – Police bombed MOVE headquarters in Philadelphia, killing six adults and five children, and destroying the homes of 250 city residents.

1862 – The USS Planter, a steamer and gunship, steals through Confederate lines and is passed to the Union, by a southern slave, Robert Smalls, who later was officially appointed as captain, becoming the first black man to command a United States ship.