On May 18, 1896, the U.S. Supreme Court, in Plessy v. Ferguson, endorsed “separate but equal” racial segregation, a concept renounced 58 years later by Brown v. Board of Education of Topeka.

In 1642, the Canadian city of Montreal was founded by French colonists. (On this date in 1765, one-quarter of Montreal was destroyed by a fire.)

In 1652, Rhode Island became the first American colony to pass a law abolishing African slavery; however, the law was apparently never enforced.

In 1863, the Siege of Vicksburg began during the Civil War, ending July 4 with a Union victory.

In 1910, Halley’s Comet passed by earth, brushing it with its tail.

In 1927, in America’s deadliest school attack, part of a schoolhouse in Bath Township, Michigan, was blown up with explosives planted by local farmer Andrew Kehoe, who then set off a bomb in his truck; the attacks killed 38 children and six adults, including Kehoe, who’d earlier killed his wife. (Authorities said Kehoe, who suffered financial difficulties, was seeking revenge for losing a township clerk election.)

In 1944, during World War II, Allied forces occupied Monte Cassino in Italy after a four-month struggle with Axis troops.

In 1953, Jacqueline Cochran, 47, became the first woman to break the sound barrier as she piloted a Canadair F-86 Sabre jet over Rogers Dry Lake, California.

In 1973, Harvard law professor Archibald Cox was appointed Watergate special prosecutor by U.S. Attorney General Elliot Richardson.

In 1980, the Mount St. Helens volcano in Washington state exploded, leaving 57 people dead or missing.

In 1981, the New York Native, a gay newspaper, carried a story concerning rumors of “an exotic new disease” among homosexuals; it was the first published report about what came to be known as AIDS.

In 2015, President Barack Obama ended long-running federal transfers of some combat-style gear to local law enforcement in an attempt to ease tensions between police and minority communities, saying equipment made for the battlefield should not be a tool of American criminal justice.

Today’s Birthdays: Actor Priscilla Pointer is 97. Baseball Hall of Famer Reggie Jackson is 75. Former Sen. Tom Udall, D-N.M., is 73. Rock singer Mark Mothersbaugh (Devo) is 71. Actor Chow Yun-Fat is 66. Comedian-writer Tina Fey is 51. Actor Spencer Breslin is 29. Actor Violett Beane is 25. Actor Hala Finley is 12.