April 20 1653 - In England, Oliver Cromwell expelled the Long Parliament for trying to pass the Perpetuation Bill that would have kept Parliament in the hands of only a few members.
April 20 1792 - France declared war on Austria, Prussia, and Sardinia. It was the start of the French Revolutionary wars.
April 20 1832 - Hot Springs National Park was established by an act of the U.S. Congress. It was the first national park in the U.S.
April 20 1841 - In Philadelphia, PA, Edgar Allen Poe’s first detective story, “The Murders in the Rue Morgue,” was published in Graham’s Magazine.
April 20 1865 - Safety matches were first advertised.
April 20 1879 - First mobile home (horse drawn) was used in a journey from London to Cyprus.
April 20 1902 - Scientists Marie and Pierre Curie isolated the radioactive element radium.
April 20 1912 - Fenway Park opened as the home of the Boston Red Sox.
April 20 1934 - The movie “Stand Up And Cheer” opened. It was Shirley Temple’s debut.
April 20 1962 - The New Orleans Citizens’ Council offered a free one-way ride for blacks to move to northern states.
April 20 1972 - The manned lunar module from Apollo 16 landed on the moon.
April 20 1977 - Woody Allen’s film “Annie Hall” premiered.
April 20 1984 - Britain announced that its administration of Hong Kong would cease in 1997.
April 20 1989 - Scientist announced the successful testing of high-definition TV.
April 20 1999 - 13 people were killed at Columbine High School in Littleton, CO, when two teenagers opened fire on them with shotguns and pipebombs. The two gunmen then killed themselves.