1901January 1901 January 1 The British colonies of New South Wales, Queensland, South Australia, Tasmania, Victoria and Western Australia federate as the Commonwealth of Australia; Edmund Barton becomes the first Prime Minister of Australia. Nigeria becomes a British protectorate. January 9 – Lord Kitchener reports that Christiaan de Wet has shot one of the "peace" envoys, and flogged two more, who had gone to his commando to ask the Burgher citizens of South Africa to halt fighting.
1904January 1904 January 7 – The distress signal CQD is established, only to be replaced 2 years later by SOS. January 8 – The Blackstone Library is dedicated, marking the beginning of the Chicago Public Library system. January 12 – The Herero Wars in German South West Africa begin. January 17 – Anton Chekhov's last play, The Cherry Orchard («Вишнëвый сад», Vishnevyi sad), opens at the Moscow Art Theatre directed by Constantin Stanislavski, 6 month's before the author's death.
1973January 1973 January 1 – The United Kingdom, the Republic of Ireland and Denmark enter the European Economic Community, which later becomes the European Union. January 15 – Vietnam War: Citing progress in peace negotiations, U.S. President Richard Nixon announces the suspension of offensive action in North Vietnam. January 17 – Ferdinand Marcos becomes President for Life of the Philippines. January 20 – Richard Nixon is sworn in for a second term as President of the United States.
19451945 marked the end of World War II and the fall of Nazi Germany and the Empire of Japan. It is also the year concentration camps were liberated and the only year in which atomic weapons have been used in combat. Below, the events of World War II have the "WWII" prefix. January 1945 January 1 – WWII: Germany begins Operation Bodenplatte, an attempt by the Luftwaffe to cripple Allied air forces in the Low Countries. Chenogne massacre: German prisoners are allegedly killed by American forces near the village of Chenogne, Belgium.
1920January 1920 January 1 Polish–Soviet War in 1920: The Russian Red Army increases its troops along the Polish border from 4 divisions to 20. Kauniainen, completely surrounded by the city of Espoo, secedes from Espoo as its own market town. January 3 – The 1920 Xalapa earthquake in Mexico kills over 600 people, making it the second deadliest in the country. January 7 – Russian Civil War: The forces of Russian White Admiral Alexander Kolchak surrender in Krasnoyarsk; the Great Siberian Ice March ensues.
1874January 1 – New York City annexes The Bronx. January 2 – Ignacio María González becomes head of state of the Dominican Republic for the first time. January 3 – Third Carlist War: Battle of Caspe – Campaigning on the Ebro in Aragon for the Spanish Republican Government, Colonel Eulogio Despujol surprises a Carlist force under Manuel Marco de Bello at Caspe, northeast of Alcañiz. In a brilliant action the Carlists are routed, losing 200 prisoners and 80 horses, while Despujol is promoted to Brigadier and becomes Conde de Caspe.