January 1, 1863
- The Emancipation Proclamation takes effect in Confederate territory.
January 1, 1959
- Fulgencio Batista, dictator of Cuba, is overthrown by Fidel Castro's forces during the Cuban Revolution.
January 2, 1788
- Georgia becomes the fourth state to ratify the United States Constitution
January 2, 1791
- Big Bottom massacre in the Ohio Country, marking the beginning of the Northwest Indian War
January 2, 1959
- Luna 1, the first spacecraft to reach the vicinity of the Moon and to orbit the Sun, is launched by the U.S.S.R.
January 4, 2004
- Spirit, a NASA Mars Rover, lands successfully on Mars at 04:35 UTC.
January 5, 1477
- Charles the Bold is killed and Burgundy becomes part of France.
January 5, 1896
- An Austrian newspaper reports that Wilhelm Roentgen has discovered a type of radiation later known as X-rays.
January 6, 1781
- In the Battle of Jersey, the British defeat the last attempt by France to invade Jersey.
January 6, 1839
- The most damaging storm in 300 years sweeps across Ireland, damaging or destroying more than 20% of the houses in Dublin.
January 7, 1610
- Galileo Galilei makes his first observation of the four Galilean moons
January 7, 1904
- The distress signal "CQD" is established only to be replaced two years later by "SOS".
January 8, 1815
- Battle of New Orleans – Andrew Jackson leads American forces in victory over the British.
January 9, 1788
- Connecticut becomes the fifth state to be admitted to the United States.
January 10, 1475
- Stephen III of Moldavia defeats the Ottoman Empire at the Battle of Vaslui.
January 10, 1920
- The Treaty of Versailles takes effect, officially ending World War I.
January 10, 1946
- The first General Assembly of the United Nations opens in the Westminster Central Hall in London.
January 12, 2004
- The world's largest ocean liner, RMS Queen Mary 2, makes its maiden voyage.
January 12, 2010
- The 2010 Haiti earthquake occurs killing an estimated 316,000 and destroying the majority of the capital Port-au-Prince.
January 13, 1893
- The Independent Labour Party of the United Kingdom holds its first meeting.
January 13, 1942
- Henry Ford patents a plastic automobile, which is 30% lighter than a regular car.
January 16, 1707
- The Scottish Parliament ratifies the Act of Union, paving the way for the creation of Great Britain.
January 16, 1909
- Ernest Shackleton's expedition finds the magnetic South Pole.
January 17, 1917
- The United States pays Denmark $25 million for the Virgin Islands.
January 17, 1949
- «The Goldbergs», the first sitcom on American television, first airs.
January 18, 1778
- James Cook is the first known European to discover the Hawaiian Islands, which he names the "Sandwich Islands".
January 20, 1265
- In Westminster, the first English parliament conducts its first meeting held by Simon de Montfort in the Palace of Westminster
January 21, 1981
- Production of the iconic DeLorean DMC-12 sports car begins in Dunmurry, Northern Ireland.
January 22, 1506
- The first contingent of 150 Swiss Guards arrives at the Vatican.
January 22, 1905
- Bloody Sunday in St. Petersburg, beginning of the 1905 revolution.
January 22, 1969
- A gunman attempts to assassinate Soviet leader Leonid Brezhnev.
January 23, 1556
- The deadliest earthquake in history, the Shaanxi earthquake, hits Shaanxi province, China.
January 24, 1848
- James W. Marshall finds gold at Sutter's Mill near Sacramento.
January 26, 1911
- Glenn H. Curtiss flies the first successful American seaplane.
January 27, 1888
- The National Geographic Society is founded in Washington, D.C..
January 28, 1820
- A Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Petrovich Lazarev discovers the Antarctic continent approaching the Antarctic coast.
January 28, 1851
- Northwestern University becomes the first chartered university in Illinois.
January 28, 1958
- The Lego company patents the design of its Lego bricks, still compatible with bricks produced today.
January 30, 1835
- In the first assassination attempt against a President of the United States, Richard Lawrence attempts to shoot president Andrew Jackson, but fails and is subdued by a crowd, including several congressmen.
January 31, 1958
- The first successful launch of an American satellite into orbit.