1866 – President of the United States of America Andrew Johnson vetoes the Civil Rights Act of 1866. His veto is overridden by Congress and the bill passes into law on April 9.

1912 – First Lady Helen Taft and the Viscountess Chinda, wife of the Japanese ambassador, plant two Yoshino cherry trees on the northern bank of the Potomac River in Washington, D.C., the origin of the National Cherry Blossom Festival.

1484 – William Caxton prints his translation of Aesop's Fables.

1812 – A political cartoon in the Boston-Gazette coins the term "gerrymander" to describe oddly shaped electoral districts designed to help incumbents win reelection.

1967 – Ten thousand people gather for one of many Central Park be-ins in New York City.

1807 – The Swansea and Mumbles Railway, then known as the Oystermouth Railway, becomes the first passenger-carrying railway in the world.

1811 – Percy Bysshe Shelley is expelled from the University of Oxford for publishing the pamphlet The Necessity of Atheism.

1911 – In New York City, the Triangle Shirtwaist Factory fire kills 146 garment workers.

1948 – The first successful tornado forecast predicts that a tornado will strike Tinker Air Force Base, Oklahoma.

1957 – United States Customs seizes copies of Allen Ginsberg's poem "Howl" on obscenity grounds.

1965 – Civil rights activists led by Martin Luther King Jr. successfully complete their 4-day 50-mile (80 km) march from Selma to the capitol in Montgomery, Alabama.

1765 – Great Britain passes the Quartering Act, which requires the Thirteen Colonies to house British troops.

1882 – Robert Koch announces the discovery of Mycobacterium tuberculosis, the bacterium responsible for tuberculosis.

1775 – American Revolutionary War: Patrick Henry delivers his speech – "Give me liberty or give me death!" – at St. John's Episcopal Church, Richmond, Virginia.

1857 – Elisha Otis's first elevator is installed at 488 Broadway New York City.

1919 – In Milan, Italy, Benito Mussolini founds his Fascist political movement.

1933 – The Reichstag passes the Enabling Act of 1933, making Adolf Hitler dictator of Germany.

1956 – Pakistan becomes the first Islamic republic in the world. This date is now celebrated as Republic Day in Pakistan.

2010 – The Affordable Care Act becomes law in the United States.

2014 – The World Health Organization (WHO) reports cases of Ebola in the forested rural region of southeastern Guinea, marking the beginning of the largest Ebola outbreak in history.

2020 – Prime Minister Boris Johnson puts the United Kingdom into its first national lockdown in response to COVID-19.

2025 – Israel Defense Forces kill 15 aid workers in the Rafah paramedic massacre.

1895 – Before the Société pour L'Encouragement à l'Industrie, brothers Auguste and Louis Lumière demonstrate movie film technology publicly for the first time.

1933 – Nazi Germany opens its first concentration camp, Dachau.

1963 – The Beatles release their debut album Please Please Me.

1988 – The United States Congress votes to override President Ronald Reagan's veto of the Civil Rights Restoration Act of 1987.

1993 – The Intel Corporation ships the first Pentium chips (80586), featuring a 60 MHz clock speed, 100+ MIPS, and a 64 bit data path.

1925 – The Butler Act prohibits the teaching of human evolution in Tennessee.

1952 – Alan Freed presents the Moondog Coronation Ball, the first rock and roll concert, in Cleveland, Ohio.

1965 – Martin Luther King Jr. leads 3,200 people on the start of the third and finally successful civil rights march from Selma to Montgomery, Alabama.

1970 – The first Earth Day proclamation is issued by Joseph Alioto, Mayor of San Francisco.

1970 – San Diego Comic-Con, the largest pop and culture festival in the world, hosts its inaugural event.

1994 – The United Nations Framework Convention on Climate Change enters into force.

1852 – Harriet Beecher Stowe's Uncle Tom's Cabin is published.

1854 – The Republican Party of the United States is organized in Ripon, Wisconsin, US.

1916 – Albert Einstein submits his paper, "The Foundation of the General Theory of Relativity", which establishes his general theory of relativity, to the journal Annalen der Physik.

1923 – The Arts Club of Chicago hosts the opening of Pablo Picasso's first United States showing, entitled Original Drawings by Pablo Picasso, becoming an early proponent of modern art in the United States.

1933 – Reichsführer-SS Heinrich Himmler orders the creation of Dachau concentration camp as Chief of Police of Munich and appoints Theodor Eicke as the camp commandant.

1948 – With a Musicians Union ban lifted, the first telecasts of classical music in the United States, under Eugene Ormandy and Arturo Toscanini, are given on CBS and NBC.

1987 – The Food and Drug Administration approves the anti-AIDS drug, AZT.

1995 – The Japanese cult Aum Shinrikyo carries out a sarin gas attack on the Tokyo subway, killing 14 and wounding over 6,200 people.

1945 – World War II: Adolf Hitler issues his "Nero Decree" ordering all industries, military installations, shops, transportation facilities, and communications facilities in Germany to be destroyed.

1979 – The United States House of Representatives begins broadcasting its day-to-day business via the cable television network C-SPAN.

1942 – The War Relocation Authority is established in the United States to take Japanese Americans into custody.

1965 – Cosmonaut Alexei Leonov, leaving his spacecraft Voskhod 2 for 12 minutes, becomes the first person to walk in space.

1966 – Off the coast of Spain in the Mediterranean, the DSV Alvin submarine finds a missing American hydrogen bomb.

1968 – As a result of nerve gas testing by the U.S. Army Chemical Corps in Skull Valley, Utah, over 6,000 sheep are found dead.

 Red_Dragon wrote:

1926 – Robert Goddard launches the first liquid-fueled rocket, at Auburn, Massachusetts.

1935 – Adolf Hitler orders Germany to rearm itself in violation of the Treaty of Versailles. Conscription is reintroduced to form the Wehrmacht.

1968 – Vietnam War: My Lai massacre occurs; between 347 and 500 Vietnamese villagers are killed by American troops.

1988 – Iran–Contra affair: Lieutenant Colonel Oliver North and Vice Admiral John Poindexter are indicted on charges of conspiracy to defraud the United States.

1995 – Mississippi formally ratifies the Thirteenth Amendment to the United States Constitution, becoming the last state to approve the abolition of slavery. The Thirteenth Amendment was officially ratified in 1865.

44 BC – The assassination of Julius Caesar, the dictator of the Roman Republic, by a group of senators takes place on the Ides of March.

1917 – Tsar Nicholas II of Russia abdicates the Russian throne, ending the 304-year Romanov dynasty.

1965 – President Lyndon B. Johnson, responding to the Selma crisis, tells the U.S. Congress "We shall overcome" while advocating the Voting Rights Act.

1990 – Mikhail Gorbachev is elected as the first and only President of the Soviet Union.

2019 – Approximately 1.4 million young people in 123 countries go on strike to protest climate change.

1903 – Pelican Island National Wildlife Refuge, the first national wildlife refuge in the US, is established by President Theodore Roosevelt.

1961 – A USAF B-52 bomber carrying nuclear weapons crashes near Yuba City, California.

1982 – The South African government bombs the headquarters of the African National Congress in London.

1781 – William Herschel discovers Uranus.

1930 – The news of the discovery of Pluto is announced by Lowell Observatory.

2003 – An article in Nature identifies the Ciampate del Diavolo as 350,000-year-old hominid footprints.

2020 – President Donald Trump declares the COVID-19 pandemic to be a national emergency in the United States.

1862 – Paddle steamer Brother Jonathan docks in Fort Victoria (now Victoria, British Columbia), carrying smallpox-infected passengers from San Francisco. The ensuing epidemic killed an estimated two-thirds of First Nations in the province of British Columbia.

1993 – North Korea announces that it will withdraw from the Treaty on the Non-Proliferation of Nuclear Weapons and refuses to allow inspectors access to its nuclear sites.

2003 – The World Health Organization officially release a global warning of outbreaks of Severe acute respiratory syndrome (SARS).

2011 – A reactor at the Fukushima Daiichi Nuclear Power Plant explodes and releases radioactivity into the atmosphere a day after the 2011 Tōhoku earthquake and tsunami.

2020 – The World Health Organization (WHO) declares the COVID-19 virus epidemic a pandemic.

1776 – Scottish philosopher Adam Smith publishes The Wealth of Nations, ushering in the classical period of political economy.

1959 – The Barbie doll makes its debut at the American International Toy Fair in New York.

1979 – Philips demonstrates the compact disc publicly for the first time.

1979 – Images taken by Voyager 1 prove the existence of volcanoes on Io, a moon of Jupiter.

2014 – In one of aviation's greatest mysteries, Malaysia Airlines Flight 370, carrying a total of 239 people, disappears en route from Kuala Lumpur to Beijing. The fate of the flight remains unknown.