April 1, 2001: Same-sex marriage becomes legal in the Netherlands, the first contemporary country to allow it.
April 2, 1800: Ludwig van Beethoven conducts the premiere of his First Symphony, in Vienna.
April 4, 1968: Martin Luther King Jr. is assassinated by James Earl Ray at a motel in Memphis, Tennessee.
April 5, 1951: Ethel and Julius Rosenberg are sentenced to death for spying for the Soviet Union.
April 6, 1973: The American League of Major League Baseball begins using the designated hitter.
April 7, 1943: In Terebovlia, Ukraine, Germans order 1,100 Jews to undress and march through the city to the nearby village of Plebanivka, where they are shot and buried in ditches.
April 8, 1974: At Atlanta–Fulton County Stadium, Hank Aaron hits his 715th career home run to surpass Babe Ruth’s 39-year-old record.
April 9, 1939: Marian Anderson sings at the Lincoln Memorial, after being denied the right to sing to an integrated audience at the Daughters of the American Revolution’s Constitution Hall. The incident places Anderson into the spotlight of the international community on a level unusual for a classical musician, especially a Black one. With the aid of First Lady Eleanor Roosevelt and her husband Franklin D. Roosevelt, Anderson performs a critically acclaimed open-air concert on Easter Sunday, on the steps of the Lincoln Memorial. She sings before a crowd of more than 75,000 people and a radio audience in the millions.
April 9, 1865: Lee surrenders to Grant ending the Civil War.
April 10, 1963: The USS Thresher is lost with 129 aboard. This is the deadliest submarine accident in history.
April 10, 1970: Paul McCartney announces that he is leaving The Beatles for personal and professional reasons.
April 11, 1976: The Apple I is created. To finance its creation, Steve Jobs sold his only motorized means of transportation, a VW Microbus, for a few hundred dollars, and Steve Wozniak sold his HP-65 calculator for $500.
April 12, 1945: FDR dies in office from a cerebral hemorrhage.
April 12, 1961: The Soviet cosmonaut Yuri Gagarin becomes the first human to travel into outer space and perform the first manned orbital flight, Vostok 1.
April 13, 1964: At the Academy Awards, Sidney Poitier becomes the first African-American male to win the Best Actor award for the 1963 film Lilies of the Field.
April 14, 1561: Around dawn, residents of Nuremberg, Germany see what they describe as an aerial battle, followed by the appearance of a large black triangular object and then a large crash outside of the city. According to witnesses, there are hundreds of spheres, cylinders and other odd-shaped objects that move erratically overhead. The phenomenon has been interpreted by some modern UFO enthusiasts as an aerial battle of extraterrestrial origin.
April 15, 1970: During the Cambodian Civil War, massacre of the Vietnamese minority results in 800 bodies flowing down the Mekong river into South Vietnam.
April 16, 1943: Albert Hofmann accidentally discovers the hallucinogenic effects of the research drug LSD, by accidentally touching his hand to his mouth. He intentionally takes the drug three days later on April 19. This day is now known as “Bicycle Day”, because he begins to feel the effects of the drug as he rides home on his bike. This is the first intentional LSD trip.
April 17, 1961: A group of Cuban exiles financed and trained by the CIA lands at the Bay of Pigs in Cuba with the aim of ousting Fidel Castro. It doesn’t end well.
April 18, 1923: The original Yankee Stadium, “The House that Ruth Built”, opens. It is the home ballpark of the New York Yankees from 1923 to 1973, and then from 1976 to 2008. The stadium is to host 6,581 Yankees regular season home games during its 85-year history. It is also known as “The Big Ballpark in The Bronx”, “The Stadium”, and "The Cathedral of Baseball”. The stadium was demolished in 2010, two years after it closed, and the 8-acre site was converted into a park called Heritage Field.