1867 1868 1869 – 1870 – 1871 1872 1873
| Decades: |
1840s 1850s 1860s – 1870s – 1880s 1890s 1900s
| Centuries: |
18th century – 19th century – 20th century
1870 was a common year starting on Saturday (see link for calendar).
Table of contents
January – April
- January 2 – Construction of the Brooklyn Bridge begins.
- January 6 – The inauguration of the Musikverein (Vienna).
- January 10 – John D. Rockefeller incorporates Standard Oil
- January 15 – A political cartoon for the first time symbolizes the United States Democratic Party with a donkey ("A Live Jackass Kicking a Dead Lion" by Thomas Nast for Harper's Weekly).
- January 26 – American Civil War: Virginia rejoins the Union
- January 27 – First college sorority, Kappa Alpha Theta, is formed at DePauw University
- February 2 – It is revealed that the famed Cardiff Giant was just carved gypsum and not the petrified remains of a human.
- February 3 – The 15th Amendment to the United States Constitution is passed
- February 10 – Anaheim, California is incorporated.
- February 10 – The YWCA is founded (New York City)
- February 12 – Women gain the right to vote in Utah Territory.
- February 23 – Military control of Mississippi ends and it is readmitted to the Union.
- February 25 – Hiram Rhoades Revels, a Republican from Mississippi, is sworn into the United States Senate, becoming the first African American ever to sit in the U.S. Congress
- February 26 – In New York City, the first pneumatic-subway is opened.
- February 28 – The Bulgarian Exarchate is established by decree of Sultan Abd-ul-Aziz of the Ottoman Empire.
- March 2 – Francisco Solano López' last troops cornered by Triple Alliance troops at Cerro Cora. López refuses to surrender and is killed. Fighting ends in Paraguay – the War of the Triple Alliance is over
- March 30 – Texas is readmitted to the Union following Reconstruction.
- April 11 – Irish peer Lord Muncaster and his entourage kidnapped in Greece
May – August
- May 12 – The Canadian province of Manitoba is created in response to Louis Riel's Red River Rebellion
- May 14 – First rugby match to be played in New Zealand, between the Nelson Football Club and Nelson College.
- June 26 – Christmas is declared a federal holiday in the United States
- July 13 – The Emser Depesche serves as a reason for a war between Prussia and France
- July 15 – Reconstruction: Georgia becomes the last former Confederate states to be readmitted to the Union, and the CSA is dissoluted.
- July 19 – Franco-Prussian War: France declares war on Prussia.
September – December
- September 2 – Franco-Prussian War: Battle of Sedan – Prussian forces defeat the French armies and take emperor Napoleon III and 100,000 of his soldiers prisoner at Sedan.
- September 4 – Emperor Napoleon III of France is deposed and the Third Republic is declared. Empress Eugenie flees to England with her children.
- September 20 – With Bersaglieri soldiers entering Rome at Porta Pia, the unification of Italy is completed. End of the temporal power of Papacy.
- October 2 – Rome becomes the capital of unified Italy
- November 1 – In the United States, the newly-created Weather Bureau (later renamed the National Weather Service) makes its first official meteorological forecast: "High winds at Chicago and Milwaukee... and along the Lakes".
- November 16 – Spanish Cortes proclaims Amadeo de Saboya as king Amadeus I of Spain.
- December – Assassination of Juan Prim, Prime minister of Spain
- January 2 – Ernst Barlach, German sculptor, graphic artist, and poet (d. 1938)
- January 8 – Miguel Primo de Rivera, dictator of Spain (d. 1930)
- February 7 – Alfred Adler, Austrian psychologist (d. 1937)
- March 5 – Frank Norris, American writer (d. 1902)
- March 17 – Horace Donisthorpe, English entomologist (d. 1951)
- March 20 – Paul Erich von Lettow-Vorbeck, German general (d. 1964)
- April 22 – Vladimir Lenin, Russian revolutionary, first leader of the Soviet Union (d. 1924)
- April 30 – Franz Lehár, Austrian composer (d. 1948)
- May 19 – Albert Fish, American serial killer (d. 1936)
- June 13 – Jules Bordet, Belgian immunologist and microbiologist (d. 1961)
- July 3 – Richard Bedford Bennett, eleventh Prime Minister of Canada (d. 1947)
- July 12 – Louis II of Monaco (d. 1949)
- July 29 – George Dixon, Canadian boxer (d. 1909)
- August 11 – Tom Richardson English cricketer (d. 1912)
- August 31 – Maria Montessori, Italian educator (d. 1952)
- September 26 – King Christian X of Denmark (d. 1947)
- October 10 – Ivan Alekseyevich Bunin, Russian writer (d. 1953)
- November 21 – Sigfrid Edström, Swedish sports official (d. 1964)
- November 27 – Juho Kusti Paasikivi, Prime Minister and President of Finland (d. 1956)
- December 5 – Vitezslav Novák, Czech composer (d. 1949)
- December 18 – Saki, English writer (d. 1918)
- January 29 – Leopold II, Grand Duke of Tuscany (b. 1797)
- February 11 – Jacob M. de Kempenaer, Dutch Minister of Internal Affairs
- February 11 – Leopold Eugen Mechura, composer
- February 19 – Nathaniel de Rothschild, French wine grower (b. 1812)
- March 28 – George Henry Thomas, American general (b. 1816)
- May 6 – Sir James Young Simpson, Scottish physician and researcher (b. 1811)
- June 9 – Charles Dickens, British novelist (b. 1812)
- July 20 – Jules Alfred Huot de Goncourt, French writer and publisher (b. 1822)
- September 12 – Fitz Hugh Ludlow, American author and explorer (b. 1836)
- September 23 – Prosper Mérimée, French writer (b. 1803)
- October 12 – Robert E. Lee, American Confederate general (b. 1807)
- November 24 – Comte de Lautreamont, French poet and writer (b. 1846)
- November 28 – Frédéric Bazille, French painter (b. 1841)
- December 5 – Alexandre Dumas, père, French author (b. 1802)
- December 27 – General Prim, Spanish dictator (b. 1814)
- Henry Rowe, architect