1898January 1 – New York City annexes land from surrounding counties, creating the City of Greater New York as the world's second largest. The city is geographically divided into five boroughs: Manhattan, Brooklyn, Queens, The Bronx and Staten Island. January 13 – Novelist Émile Zola's open letter to the President of the French Republic on the Dreyfus affair, J'Accuse...!, is published on the front page of the Paris daily newspaper L'Aurore, accusing the government of wrongfully imprisoning Alfred Dreyfus and of antisemitism.
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.
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.
1887January 11 – Louis Pasteur's anti-rabies treatment is defended in the Académie Nationale de Médecine, by Dr. Joseph Grancher. January 20 The United States Senate allows the Navy to lease Pearl Harbor as a naval base. British emigrant ship Kapunda sinks after a collision off the coast of Brazil, killing 303 with only 16 survivors. January 21 The Amateur Athletic Union (AAU) is formed in the United States. Brisbane receives a one-day rainfall of (a record for any Australian capital city).
1903January 1903 January 1 – Edward VII is proclaimed Emperor of India. January 4 – Topsy, a female Asian circus elephant, is killed by electrocution at Luna Park, Coney Island, New York City. January 19 – The first west–east transatlantic radio broadcast is made from the United States to England (the first east–west broadcast having been made in 1901). January 17 – 13 days after Topsy's death, the Edison Manufacturing Company released the short, black-and-white, silent documentary film Electrocuting an Elephant, showing the footage of Topsy's electrocution.
1883January 4 – Life magazine is founded in Los Angeles, California, United States. January 10 – A fire at the Newhall Hotel in Milwaukee, Wisconsin, United States, kills 73 people. January 16 – The Pendleton Civil Service Reform Act, establishing the United States civil service, is passed. January 19 – The first electric lighting system employing overhead wires begins service in Roselle, New Jersey, United States, installed by Thomas Edison. February – The Adventures of Pinocchio by Carlo Collodi is first published complete in book form, in Italy.