April in History

President Richard Nixon signs the Public Health Cigarette Smoking Act into law.

Having spotted land on March 27, Spanish explorer Juan Ponce de León comes ashore on what is now the U.S. state of Florida, landing somewhere between the modern city of St. Augustine and the mouth of the St. Johns River.

First flight over Mount Everest, the British Houston-Mount Everest Flight Expedition, led by the Marquis of Clydesdale and funded by Lucy, Lady Houston.

Napoleon abdicates (conditionally) for the first time and names his son Napoleon II as Emperor of the French, followed by unconditional abdication two days later.

Carrie, the first novel by American author Stephen King, is published for the first time with a print run of 30,000 copies.

British forces under the command of the Duke of Wellington assault the fortress of Badajoz. This would be the turning point in the Peninsular War against Napoleon-led France.

Violet Gibson attempts to assassinate Italian Prime Minister Benito Mussolini.

The Venus de Milo is discovered on the Aegean island of Milos.

The Journey of Reconciliation, the first interracial Freedom Ride begins through the upper South in violation of Jim Crow laws. The riders wanted enforcement of the United States Supreme Court's 1946 Irene Morgan decision that banned racial segregation in interstate travel.

Paul McCartney announces that he is leaving The Beatles for personal and professional reasons.

The Treaty of Fontainebleau ends the War of the Sixth Coalition against Napoleon Bonaparte, and forces him to abdicate unconditionally for the first time.

Harold Washington is elected as the first black mayor of Chicago.

World War II: The discovery of mass graves of Polish prisoners of war killed by Soviet forces in the Katyń Forest Massacre is announced, causing a diplomatic rift between the Polish government-in-exile in London and the Soviet Union, which denies responsibility.

Muslims in the Ottoman Empire begin a massacre of Armenians in Adana.

Battle of Rain: Swedes under Gustavus Adolphus defeat the Holy Roman Empire during the Thirty Years' War.

U.S. civil rights campaigner Dr. Martin Luther King Jr. writes his open letter from Birmingham Jail, sometimes known as "The Negro Is Your Brother", while incarcerated in Birmingham, Alabama, for protesting against segregation.

NASA's Kepler space telescope confirms the discovery of the first Earth-size planet in the habitable zone of another star.

The Israeli military commits the Qana massacre in a deliberate shelling of a United Nations compound near the village of Qana in southern Lebanon, killing 106 Lebanese civilians who were taking shelter there and wounding over 100 more.

India's first satellite Aryabhata launched in orbit from Kapustin Yar, Russia.

Two Austrian army corps in Bavaria are defeated by a First French Empire army led by Napoleon at the Battle of Abensberg on the second day of a four-day campaign that ended in a French victory.

The controversial Kharkiv Pact (Russian Ukrainian Naval Base for Gas Treaty) is signed in Kharkiv, Ukraine, by Ukrainian president Viktor Yanukovych and Russian president Dmitry Medvedev; it was unilaterally terminated by Russia on March 31, 2014.

Portuguese navigator Pedro Álvares Cabral lands in Brazil (discovery of Brazil).

The Grand National Assembly of Turkey (TBMM) is founded in Ankara. The assembly denounces the government of Sultan Mehmed VI and announces the preparation of a temporary constitution.

The United States Library of Congress is established when President John Adams signs legislation to appropriate $5,000 to purchase "such books as may be necessary for the use of Congress".

The Battle of Bagrevand puts an end to an Armenian rebellion against the Abbasid Caliphate. Muslim control over the South Caucasus is solidified and its Islamization begins, while several major Armenian nakharar families lose power and their remnants flee to the Byzantine Empire.

The Gestapo, the official secret police force of Nazi Germany, is established by Hermann Göring.

First Barbary War: United States Marines and Berbers attack the Tripolitan city of Derna (The "shores of Tripoli" in the Marines' Hymn).

The Sino-Japanese Peace Treaty (Treaty of Taipei) is signed in Taipei, Taiwan between Japan and the Republic of China to officially end the Second Sino-Japanese War.

James Cook arrives in Australia at Botany Bay, which he names.

On the balcony of Federal Hall on Wall Street in New York City, George Washington takes the oath of office to become the first President of the United States.