---

Our on this day in history archives contain over 200,000 events, birthdays and deaths from 6,000 years of history. Here is a roundup of a few more of them:

May 1 is the 121st day of the year (122nd in leap years) in the Gregorian calendar; 244 days remain until the end of the year.

EVENTS

305 – Diocletian and Maximian retire from the office of Roman emperor.

1486 – Christopher Columbus presents his plans discovering a western route to the Indies to the Spanish Queen Isabella I of Castile.

1707 – The Act of Union joining England and Scotland to form the Kingdom of Great Britain takes effect.

1753 – Publication of Species Plantarum by Linnaeus, and the formal start date of plant taxonomy adopted by the International Code of Botanical Nomenclature.

1840 – The Penny Black, the first official adhesive postage stamp, is issued in the United Kingdom.

1844 – Hong Kong Police Force, the world's second modern police force and Asia's first, is established.

1851 – Queen Victoria opens The Great Exhibition at The Crystal Palace in London.

1863 – American Civil War: The Battle of Chancellorsville begins.

1866 – The Memphis Race Riots begin. Over three days, 46 blacks and two whites were killed. Reports of the atrocities influenced passage of the Fourteenth Amendment to the United States Constitution.

1885 – The original Chicago Board of Trade Building opens for business.

1886 – Rallies are held throughout the United States demanding the eight-hour work day, culminating in the Haymarket affair in Chicago, in commemoration of which May 1 is celebrated as International Workers' Day in many countries.

1894 – Coxey's Army, the first significant American protest march, arrives in Washington, D.C.

1898 – Spanish–American War: Battle of Manila Bay: The Asiatic Squadron of the United States Navy destroys the Pacific Squadron of the Spanish Navy after a seven-hour battle. Spain loses all seven of its ships, and 381 Spanish sailors die. There are no American vessel losses or combat deaths.

1900 – The Scofield Mine disaster kills over 200 men in Scofield, Utah in what is to date the fifth-worst mining accident in United States history.

1915 – RMS Lusitania departs from New York City on her 202nd, and final, crossing of the North Atlantic. Six days later, the ship is torpedoed off the coast of Ireland with the loss of 1,198 lives.

1930 – "Pluto" is officially proposed for the name of the newly discovered dwarf planet by Vesto Slipher in the Lowell Observatory Observation Circular. The name quickly catches on.

1931 – The Empire State Building is dedicated in New York City.

1956 – The polio vaccine developed by Jonas Salk is made available to the public.

1961 – The Prime Minister of Cuba, Fidel Castro, proclaims Cuba a socialist nation and abolishes elections.

1971 – Amtrak (the National Railroad Passenger Corporation) takes over operation of U.S. passenger rail service.

1999 – The body of British climber George Mallory is found on Mount Everest, 75 years after his disappearance in 1924.

2003 – Invasion of Iraq: In what becomes known as the "Mission Accomplished" speech, on board the USS Abraham Lincoln (off the coast of California), U.S. President George W. Bush declares that "major combat operations in Iraq have ended".

2011 – Pope John Paul II is beatified by his successor, Pope Benedict XVI.

---

---