1802: German astronomer Heinrich Wilhelm Matthäus Olbers (1758-1840) of Bremen discovered the second asteroid known to man, dubbed 2 Pallas.
1814: The Royal Navy of the United Kingdom defeated the U.S. Navy in the Battle of Valparaiso, Chile, during the War of 1812.
1862: Union forces stopped the Confederate invasion of New Mexico, in the Battle of Glorieta Pass, which began two days earlier.
1910: Henri Fabre (1882-1984) became the first person to fly a seaplane, the Fabre Hydravion, after taking off from a water runway near Martigues, France.
1930: Constantinople, Turkey, changed its name to Istanbul, signaling the end of the Ottoman Empire.
1969: Dwight David Eisenhower (34th U.S. president, 1953-1961) died in Washington, D.C., age 78. 1979: The worst nuclear power plant accident in American history occurred at Three Mile Island near Harrisburg, Pa.
2006: Massive protests are mounted against France’s first employment contract law, meant to reduce youth unemployment.
1638: Swedish colonists established the first European settlement in Delaware, naming it New Sweden.
1806: Construction was authorized of the Great National Pike, better known as the Cumberland Road, which became the first U.S. federal highway.
1886: Dr. John Pemberton (chemist) brewed the first batch of Coca-Cola in a backyard in Atlanta, Georgia.
1911: The M1911 .45 ACP pistol became the official U.S. Army side arm.
1919: The first Ringling Brothers and Barnum & Bailey Circus was held.
1957: The first major U.S. railroad abandonment in its entirety occurred when the New York, Ontario and Western Railway made its final run.
1961: The 23rd Amendment to the U.S. Constitution was ratified, allowing residents of Washington, D.C., to vote in presidential elections.
1971: A jury in Los Angeles, Calif., recommended the death penalty for Charles Manson and his female devotees Susan Adkins, Patricia Krenwinkle and Leslie Van Houten. U.S. Army Lt. William Calley was convicted of premeditated murder in the My Lai Massacre and sentenced to life in prison.
1974: NASA’s Mariner 10 became the first space probe to fly by Mercury.
1993: Catherine Callbeck became premier of Prince Edward Island, as well as the first woman elected in a general election as premier of a Canadian province.
2004: The Republic of Ireland became the first country in the world to ban smoking in all work places, including bars and restaurants.
1822: The Florida Territory was created in the United States.
1842: Ether anesthesia was used for the first time, in an operation at Massachusetts General Hospital by U.S. surgeon Dr. Crawford Long (1815-1878).
1867: Alaska was purchased from Russia for $7.2 million, about 2 cents per acre by U.S. Secretary of State William H. Seward.
1870: Texas was readmitted to the Union.
1909: The Queensboro Bridge in New York City opened, linking Manhattan and Queens.
1954: The Yonge Street subway line opened in Toronto, becoming the first subway in Canada.
1964: The TV game show Jeopardy! premiered with host Art Fleming and announcer Don Pardo.
2017: SpaceX conducts the worlds first re-flight of an orbital class rocket.
1889: The Eiffel Tower officially opened.
1903: Richard Pearse allegedly made a powered flight in an early aircraft in New Zealand.
1906: The Intercollegiate Athletic Association of the United States (later the National Collegiate Athletic Association) was established to set rules for college sports in the United States.
1909: Construction of the ill-fated RMS Titanic began in Belfast, Northern Ireland.
1917: The United States took possession of the Danish West Indies after paying $25 million to Denmark, and renamed the territory the United States Virgin Islands.
1918: Daylight saving time went into effect in the United States for the first time.
1930: The Motion Picture Production Code was instituted, imposing strict guidelines on the treatment of sex, crime, religion and violence in film, in the United States, for the next 38 years.
1933: The Civilian Conservation Corps was established to relieve widespread unemployment in the United States.
1945: In the final month of World War II in Europe, a defecting German pilot delivered a Messerschmitt Me 262A-1, the world’s first operational jet-powered fighter aircraft, to the Americans, the first to fall into Allied hands.
1949: The Dominion of Newfoundland joined the Canadian Confederation and became the 10th province of Canada.
1951: Remington Rand, an early American business machines manufacturing company, delivered the first UNIVAC I computer to the United States Census Bureau.
1966: The Soviet Union launched Luna 10, which later became the first space probe to enter orbit around the Moon.
1985: The first WrestleMania, the biggest wrestling event from the WWF (now the WWE), took place in Madison Square Garden in New York.
1992: The USS Missouri, the last active United States Navy battleship, was decommissioned in Long Beach, Calif.
A.D. 40: The first recorded April Fools Day joke took place in Rome, when Emperor Caligula said to his uncle, Claudius, “Braccae tuae aperiuntur” (“Your fly is open”).
1519: Hernán Cortez of Spain introduced smallpox to the Aztec Indians of Mexico.
1826: Samuel Morey patented the internal combustion engine.
1867: Singapore became a British crown colony.
1891: The Wrigley Company was founded in Chicago, Illinois.
1924: Adolf Hitler was sentenced to five years in jail for his participation in the “Beer Hall Putsch,” however, he spent only nine months in jail, during which he wrote his infamous racist screed Mein Kampf.
1947: The only mutiny in the history of the Royal New Zealand Navy began.
1949: The 26 counties of the Irish Free State became the Republic of Ireland.
1954: President Dwight D. Eisenhower authorized the creation of the United States Air Force Academy in Colorado.
1955: Born this day: NFL player Don Hasselbeck.
1957: The BBC broadcast the spaghetti-tree hoax as an April Fools’ Day joke on its current affairs program Panorama; the program purportedly showed a family in southern Switzerland harvesting spaghetti from the family “spaghetti tree.” (Decades later, CNN called this broadcast “the biggest hoax that any reputable news establishment ever pulled.”)
1960: The U.S.-launched TIROS-1 satellite transmitted the first television picture from space.
1967: The United States Department of Transportation began operation.
1970: President Richard Nixon signed the Public Health Cigarette Smoking Act into law, requiring the surgeon general’s warnings on tobacco products and banning cigarette advertisements on television and radio in the United States, starting on Jan. 1, 1971.
1973: Project Tiger, a tiger conservation project, was launched in the Jim Corbett National Park in India.
1975: Producer Lorne Michaels signed a deal with NBC to produce what would become Saturday Night Live.
1976: Apple Inc. was formed by Steve Jobs, Steve Wozniak and Ronald Wayne in Cupertino, Calif. Conrail took over operations from six bankrupt railroads in the Northeastern U.S. 1976 – The Jovian-Plutonian gravitational effect, soon revealed as an April Fools’ Day hoax, was first reported by British astronomer Patrick Moore.
1982: Ronald Reagan became the first president to address both houses of Congress wearing fuzzy bunny slippers.
1997: Comet Hale-Bopp is seen passing at its closest point to the Sun.
2001: Same-sex marriage became legal in the Netherlands, the first contemporary country to allow it.
2004: Google unveiled Gmail to the public.
1800: Ludwig van Beethoven led the premiere of his First Symphony in Vienna, Austria.
1863: Food shortages incited hundreds of angry women to riot in Richmond, Virginia, and demand that the Confederate government release emergency supplies.
1902: Electric Theatre, the first full-time movie theater in the United States, opened in Los Angeles, Calif.
1912: The ill-fated RMS Titanic began sea trials.
1956: As the World Turns and The Edge of Night premiered on CBS-TV as the first daytime dramas in the 30-minute format.
1991: Rita Johnston became the first female premier of a Canadian province when she succeeded William Vander Zalm (who had resigned) as premier of British Columbia.
2006: Over 60 tornadoes broke out in the United States.
1860: The first successful United States Pony Express run began from St. Joseph, Mo., to Sacramento, Calif.
1912: Calbraith Perry Rodgers became the first pilot to die in an airplane crash as a result of colliding with birds, in Long Beach, Calif.
1933: The Marquis of Clydesdale led an expedition in the first flight over Mount Everest.
1961: The Leadbeater’s possum, once feared extinct, was rediscovered in Australia after 72 years
1968: Martin Luther King Jr. delivered his “I’ve Been to the Mountaintop” speech in Memphis, Tenn.
1973: Martin Cooper of Motorola made the first handheld mobile phone call to Joel S. Engel of Bell Labs.
1981: The Osborne 1, the first successful portable computer, was unveiled at the West Coast Computer Faire in San Francisco.
2010: Apple Inc. released the first generation iPad, a tablet computer.