1904
Events
January
- January 7 – The distress signal CQD is established, only to be replaced 2 years later by SOS.
- January 12 – The Herero Wars in German South West Africa begin.
- January 17 – Anton Chekhov's last play, The Cherry Orchard, opens at the Moscow Art Theatre directed by Constantin Stanislavski.
- January 23 – The Ålesund fire destroys most buildings in the town of Ålesund, Norway, leaving about 10,000 people without shelter.
- January 25 – Halford Mackinder presents a paper on "The Geographical Pivot of History" to the Royal Geographical Society of London in which he formulates the Heartland Theory, originating the study of geopolitics.
February
- February 7 – The Great Baltimore Fire in Baltimore, Maryland, destroys over 1,500 buildings in 31 hours.
- February 8–9 – Battle of Port Arthur: A surprise Japanese naval attack on Port Arthur in Manchuria starts the Russo-Japanese War.
- February 10 – Roger Casement publishes his account of Belgian atrocities in the Congo.
- February 17 – Puccini's opera Madama Butterfly debuts at La Scala in Milan, to no great acclaim. On May 28 a revised version opens in Brescia, to huge success.
- February 23 – For $10 million, the United States gains control of the Panama Canal Zone.
- February 28 – S.L. Benfica, one of the biggest Association Football clubs in Portugal, is founded as Sport Lisboa.
March
- March 3 – Kaiser Wilhelm II of Germany becomes the first person to make a recording of a political document, using Thomas Edison's cylinder.
- March 6 – Scottish National Antarctic Expedition: Led by William Speirs Bruce, the Antarctic region of Coats Land is discovered from the Scotia.
- March 31 – British expedition to Tibet: The Battle of Guru – British troops under Colonel Francis Younghusband defeat ill-equipped Tibetan troops.
April
- April 4 – 1904 Kresna earthquakes: two earthquakes strike near Kresna, Bulgaria, killing at least 200 people.
- April 6 – Joseph F. Smith announces the Second Manifesto in General Conference of the Church of Jesus Christ of Latter-day Saints in Utah Territory, prohibiting the practice of polygamy, which has continued to be sanctioned by some of its leaders in violation of the 1890 Manifesto officially banning the practice.
- April 8
- * The Entente Cordiale is signed between the UK and France.
- * Longacre Square in Midtown Manhattan is renamed Times Square, after The New York Times.
- April 8–10 – Aleister Crowley writes The Book of the Law, a text central to Thelema, in Cairo.
- April 19 – The Great Fire of Toronto destroys much of the city's downtown, but there are no fatalities.
- April 27 – The Australian Labor Party becomes the first such party to gain national government, under Chris Watson.
- April 30 – The Louisiana Purchase Exposition World's Fair opens in St. Louis, Missouri.
May
- May 4
- * United States Army engineers begin work on the Panama Canal.
- * Charles Rolls and Henry Royce meet for the first time, in Manchester England to agree production of Rolls-Royce motor cars; the first produced under their joint names are launched in December.
- * German Association football club FC Schalke 04 is established.
- May 5
- * British expedition to Tibet: Hundreds of Tibetans attack the British camp at Changlo, and hold the advantage for a while, before being defeated by superior weapons, and losing at least 200 men.
- * Pitching against the Philadelphia Athletics, Cy Young of the Boston Americans throws the first perfect game in the modern era of baseball.
- May 9 – Great Western Railway of England 3700 Class 3440 City of Truro possibly becomes the first railway locomotive to exceed.
- May 15 – Russo-Japanese War: Russian minelayer Amur lays a minefield about off Port Arthur, and sinks Japan's battleships Hatsuse, 15,000 tons with 496 crew, and Yashima. On the same day, the Japanese protected cruiser Yoshino sinks after being accidentally rammed by the armored cruiser Kasuga, killing over 270 crew, including Captain Sayegi and his second-in-command, Commander Hirowateri. Japan will keep the loss of Yashima secret for over a year.
- May 21 – The International Federation of Association Football, FIFA, is established.
- May 30 – Alpha Gamma Delta, which becomes an international sorority, is founded by 11 women at Syracuse University.
June
- June 3 – The International Alliance of Women is founded.
- June 15 – A fire aboard the steamboat General Slocum in New York City's East River kills 1,021.
- June 16
- * Finnish nationalist Eugen Schauman assassinates Nikolay Bobrikov, the Russian Governor-General of Finland, in Helsinki.
- * The original "Bloomsday", the day James Joyce first walks out with his future wife Nora Barnacle, to the Dublin suburb of Ringsend. He sets the action of his novel Ulysses on this date.
- June 28
- * Danish ocean liner runs aground and sinks close to Rockall, killing approximately 627 people, many of whom are Russian-Polish and Scandinavian emigrants.
- * The original icon of Our Lady of Kazan is stolen and subsequently destroyed in Russia.
- * English Association football club Hull City A.F.C. is established.
- June 29 – The 1904 Moscow tornado occurs.
- July – Pavlos Melas enters Macedonia with a small unit of men during the Macedonian Struggle.
- July 1 – The third Modern Olympic Games open in St. Louis, Missouri, United States, as part of the World's Fair.
- July 22 – The first 2,000 of 62,000 contracted Chinese coolies arrive at Durban in South Africa from Qinhuangdao to relieve the shortage of unskilled labourers in the Transvaal Colony gold mines, recruited and shipped by the Chinese Engineering and Mining Corporation, of which Herbert Hoover is a director.
- July 23 – A continuous track tractor is patented by David Roberts of Richard Hornsby & Sons of Grantham in England.
August
- August 3 – British expedition to Tibet: The British expedition under Colonel Francis Younghusband takes Lhasa, Tibet.
- August 11 – Battle of Waterberg: Lothar von Trotha defeats the Herero people in German South West Africa, and drives them into the Omaheke desert, starting the Herero and Namaqua genocide.
- August 14 – Ismael Montes becomes President of Bolivia.
- August 17 – Russo-Japanese War: A Japanese infantry charge fails to take Port Arthur.
- August 24 – Faroese Association football club Klaksvíkar Ítróttarfelag is established.
- Summer – Henri Matisse paints Luxe, Calme et Volupté at Saint-Tropez; it will be considered the starting point of Fauvism.
September
- September – Stuyvesant High School opens in New York City as Manhattan's first manual trade school for boys.
- September 1 – Griffin Park football ground, home of Brentford F.C., opens in London.
- September 2 – John Voss sails the rigged dugout canoe Tilikum into the River Thames in England after a 3-year voyage from Victoria, British Columbia, westabout.
- September 7 – British expedition to Tibet: The Dalai Lama signs the Anglo-Tibetan Treaty with Colonel Francis Younghusband.
- September 17 – An early study on the relationship between alcohol and cardiovascular disease is published in the United States.
- September 26 – New Zealand dolphin Pelorus Jack is individually protected by Order in Council under the Sea Fisheries Act.
October
- October – The Daytona Educational and Industrial Training School for Negro Girls, predecessor of Bethune–Cookman University, is opened in Florida by Mary McLeod Bethune.
- October 1 – Phi Delta Epsilon, the international medical fraternity, is founded by Aaron Brown and 8 of his friends, at Cornell University Medical College.
- October 4 – Swedish Association football club IFK Göteborg is founded, becoming the 39th IFK-association.
- October 5 – Alpha Kappa Psi, a co-ed professional business fraternity, is founded on the campus of New York University.
- October 9 – German journalist Anna Rüling, in a speech to the Scientific-Humanitarian Committee in Berlin, makes the first known public statement of the socio-legal problems faced by lesbians.
- October 11 – Loftus Road football stadium opens in London.
- October 13 – Pavlos Melas is encircled at Statista and killed during the Macedonian Struggle.
- October 15 – Theta Tau, a professional engineering fraternity, is founded at the University of Minnesota in Minneapolis.
- October 18 – In Germany:
- * The Kaiser-Friedrich-Museum opens in Berlin for the display of fine art.
- * Gustav Mahler's Symphony No. 5 is premiered by the Gürzenich Orchestra Cologne.
- October 19 – Polytechnic University of the Philippines is founded as Manila Business School, through the superintendence of American C. A. O'Reilley.
- October 21 – Russo-Japanese War: Dogger Bank incident – The Russian Baltic Fleet fires on British trawlers it mistakes for Japanese torpedo boats, in the North Sea.
- October 27 – The first underground line of the New York City Subway opens.
- October 28 – Panama and Uruguay establish diplomatic relations.
- Late October – The first members of what will become the Bloomsbury Group move to the Bloomsbury district of London; they will be joined about November 8 by the future novelist Virginia Woolf.
November
- November 8 – 1904 United States presidential election: Republican incumbent Theodore Roosevelt defeats Democrat Alton B. Parker.
- November 16
- * The settlement at Grytviken, on the British South Atlantic island territory of South Georgia, is established by Norwegian sea captain Carl Anton Larsen, as a whaling station for his Compañía Argentina de Pesca.
- * English engineer John Ambrose Fleming patents the first thermionic vacuum tube, the two-electrode diode.
- November 24 – A continuous track tractor is successfully demonstrated by the Holt Manufacturing Company in the United States. The "caterpillar track" will come to revolutionize construction vehicles and land warfare.
File:Leclerc p1040868.jpg|thumb|180px|right| July 23 & November 24: continuous track