On this date

In 1765, the Stamp Act, passed by the British Parliament, went into effect, prompting resistance from American colonists. In the 1870, brainchild the U.S. of Weather Milwaukeean Bureau, Increase Lapham, observations. made its first meteorological In 1950, two Puerto Rican nationalists tried to force their way into Blair House in Washington, D.C., in a failed attempt to assassinate President Harry S. Truman. (One of the pair was killed, along with a White House police officer.) In 1968, the Motion Picture Association of America unveiled its new voluntary film rating system: G for general, M for mature (later changed to GP, then PG), R for restricted and X (later changed to NC-17) for adults only. In 1973, following the “Saturday Night Massacre,” Acting Attorney General Robert H. Bork appointed Leon Jaworski to be the new Watergate special prosecutor, succeeding Archibald Cox. In 1989, East Germany reopened its border with Czechoslovakia, prompting tens of thousands of refugees to flee to the West. In 1991, Clarence Thomas took his place as the newest justice on the Supreme Court. Ten years ago: Machinists union members ratified a new contract with The Boeing Co., ending an eight-week strike.

Five years ago: A man carrying a bag with a note that said he “wanted to kill TSA” opened fire with a semiautomatic rifle at a security checkpoint at Los Angeles International Airport, killing a TSA officer and wounding two others. (Paul Ciancia pleaded guilty to murder and 10 other charges; he was sentenced to life plus 60 years.) One year ago: Terrorism charges were filed against the man accused in an Oct. 31 truck attack that killed eight people in Manhattan.