- 1791 The Constitution of May 3 (the first modern constitution in Europe) is proclaimed by the Sejm of Polish-Lithuanian Commonwealth.
- 1926 British General Strike: Trade Union Congress calls for a general strike 1 minute to midnight to support striking coal miners
- 1937 Margaret Mitchell wins Pulitzer Prize for "Gone With the Wind"
- 1945 World War II: German ship "Cap Arcona" laden with prisoners sunk by Royal Air Force in East Sea, 5,800 killed - one of largest maritime losses of life
- 1947 Japan's post-war constitution goes into effect, granting universal suffrage, stripping Emperor Hirohito of all but symbolic power and outlawing Japan's right to make war
Day depicted by Spanish painter Goya in his "The Third of May", painted 1814
On May 3, 1808
First unsolicited bulk commercial e-mail ("spam") is sent by a Digital Equipment Corporation marketing representative to every ARPANET address on the US west coast
On May 3, 1978