Today in history
On May 22, 1968, the nuclear-powered submarine USS Scorpion, with 99 men aboard, sank in the Atlantic Ocean. (The remains of the sub were later found on the ocean floor 400 miles southwest of the Azores.)
In 1761, the first American life insurance policy was issued in Philadelphia to a Rev. Francis Allison, whose premium was six pounds per year.
In 1868, a major train robbery took place near Marshfield, Indiana, as members of the Reno gang made off with $96,000 in loot.
In 1913, the American Cancer Society was founded in New York under its original name, the American Society for the Control of Cancer.
In 1939, the foreign ministers of Germany and Italy, Joachim von Ribbentrop and Galeazzo Ciano, signed a "Pact of Steel" committing the two countries to a military alliance.
In 1947, the Truman Doctrine was enacted as Congress appropriated military and economic aid for Greece and Turkey.
In 1960, an earthquake of magnitude 9.5, the strongest ever measured, struck southern Chile, claiming some 1,655 lives.
In 1969, the lunar module of Apollo 10, with Thomas P. Stafford and Eugene Cernan aboard, flew to within nine miles of the moon's surface in a dress rehearsal for the first lunar landing.
In 1972, President Richard Nixon began a visit to the Soviet Union, during which he and Kremlin leaders signed the Anti-Ballistic Missile Treaty. The island nation of Ceylon became the republic of Sri Lanka.
In 1981 "Yorkshire Ripper" Peter Sutcliffe was convicted in London of murdering 13 women and was sentenced to life in prison.
In 1992, after a reign lasting nearly 30 years, Johnny Carson hosted NBC's "Tonight Show" for the final time (Jay Leno took over as host three days later).
In 1998, a federal judge ruled that Secret Service agents could be compelled to testify before the grand jury in the Monica Lewinsky investigation. Voters in Northern Ireland and the Republic of Ireland turned out to cast ballots giving resounding approval to a Northern Ireland peace accord.
In 2011, a tornado devastated Joplin, Missouri, with winds up to 250 mph, claiming at least 159 lives and destroying about 8,000 homes and businesses.
Ten years ago: A Texas appeals court said the state had no right to take more than 400 children from a polygamist group's ranch the previous month; the children were returned to their parents. Britain's Conservative Party won a special election that was viewed as a rebuke to Prime Minister and Labour Party leader Gordon Brown.
Five years ago: Lois Lerner, an Internal Revenue Service supervisor whose agents had targeted conservative groups, swore to a House committee she did nothing wrong, then refused to answer further questions, citing her Fifth Amendment right not to incriminate herself. In a brutal daylight attack in London, two al-Qaida-inspired extremists with butcher knives hacked to death an off-duty British soldier, Lee Rigby, before police wounded them in a shootout. (The attackers were later sentenced to prison.)
One year ago: A suicide bomber set off an improvised explosive device that killed 22 people at the end of an Ariana Grande concert in Manchester, England. In a historic gesture, President Donald Trump solemnly placed a note in the ancient stones of Jerusalem's Western Wall. Ford Motor Co. announced it was replacing CEO Mark Fields. Actress Dina Merrill, 93, died at her home in East Hampton, New York.