February 4 is the 35th day of the year. There are 331 days remaining until the end of the year.
February 4 is World Cancer Day.
- 1703 – In Edo, Japan, 46 of the Forty-seven Ronin were forced to commit seppuku (ritual suicide) for avenging their master's death.
- 1789 – George Washington was unanimously elected the first President of the United States by the Electoral College, the only President to receive 100% of the Electoral College votes.
- 1794 – The French legislature abolished slavery throughout the French Republic.
- 1859 – The Codex Sinaiticus, the best Greek text of the New Testament, was discovered in Egypt.
- 1861 – The Confederate States of America was formed in Montgomery, Alabama.
- 1936 – Radium became the first radioactive element to be made synthetically.
- 1941 – The Untied Service Organization (USO) was created to entertain American troops.
- 1945 – The Yalta Conference between the "Big Three" (Churchill, Roosevelt, and Stalin) opened at the Livadia Palace in the Crimea.
- 2004 - Facebook, an online social network, was founded by Mark Zuckerberg.