1875January 1 – The Midland Railway of England abolishes the Second Class passenger category, leaving First Class and Third Class. Other British railway companies follow Midland's lead during the rest of the year (Third Class is renamed Second Class in 1956). January 5 – The Palais Garnier, one of the most famous opera houses in the world, is inaugurated as the home of the Paris Opera. January 12 – Guangxu becomes the 11th Qing dynasty Emperor of China at the age of 3, in succession to his cousin.
1899January 1 Spanish rule ends in Cuba, concluding 400 years of the Spanish Empire in the Americas. Queens and Staten Island become administratively part of New York City. January 2 Bolivia sets up a customs office in Puerto Alonso, leading to the Brazilian settlers there to declare the Republic of Acre in a revolt against Bolivian authorities. The first part of the Jakarta Kota–Anyer Kidul railway on the island of Java is opened between Batavia Zuid (Jakarta Kota) and Tangerang.
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.
1905As the second year of the massive Russo-Japanese War begins, more than 100,000 die in the largest world battles of that era, and the war chaos leads to the 1905 Russian Revolution against Nicholas II of Russia (Shostakovich's 11th Symphony is subtitled The Year 1905 to commemorate this) and the start of Revolution in the Kingdom of Poland. Canada and the U.S. expand west, with the Alberta and Saskatchewan provinces and the founding of Las Vegas.
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.
1881January 1–24 – Siege of Geok Tepe: Russian troops under General Mikhail Skobelev defeat the Turkomans. January 13 – War of the Pacific – Battle of San Juan and Chorrillos: The Chilean army defeats Peruvian forces. January 15 – War of the Pacific – Battle of Miraflores: The Chileans take Lima, capital of Peru, after defeating its second line of defense in Miraflores.
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.