1st January » Adolf Loos, architect, co-founder of modern architecture, baptized in Church of St. Thomas (Brno) called St. Thomas church, Brno, Moravia
3rd January » Construction of the Brooklyn Bridge begins.
6th January » The inauguration of the Musikverein in Vienna or Vienna, Austria.
10th January » John D. Rockefeller incorporates Standard Oil.
23rd January » In Montana, U.S. cavalrymen kill 173 Native Americans in the United States e.g Native Americans, mostly women and children, in what becomes known as the Marias Massacre.
26th January » American Civil War: Virginia History of Virginia Reconstruction named rejoins the Union.
27th January » The Kappa Alpha Theta fraternity is founded at DePauw University.
3rd February » The Fifteenth Amendment to the United States Constitution is ratified, guaranteeing voting rights to citizens regardless of race.
9th February » President Ulysses S. Grant signs a joint resolution of United States Congress or Congress establishing the U.S. Weather Bureau.
10th February » The YWCA is founded in New York City.
15th February » Stevens Institute of Technology is founded and offers the first Bachelors of Engineering in Mechanical Engineering.
23rd February » Reconstruction Era: Post-American Civil War or U.S. Civil War military control of Mississippi ends and it is readmitted to the Union (American Civil War) e.g Union.
25th February » Hiram Rhodes Revels, a Republican Party (United States) named Republican from Mississippi, is sworn into the United States Senate, becoming the first African American ever to sit in the Congress of the United States or U.S. Congress.
27th February » The current flag of Japan is first adopted as the national flag for Japanese merchant ships.
28th February » The Bulgarian Exarchate is established by decree of Sultan Abd-ul-Aziz of the Ottoman Empire.
1st March » Francisco Solano López (politician) named Marshal F.S. López dies during the Battle of Cerro Corá thus marking the end of the Paraguayan War.
30th March » Texas is readmitted to the Union (American Civil War) called Union following Reconstruction era (United States) or Reconstruction.
13th April » The New York City Metropolitan Museum of Art is founded.
12th May » The Manitoba Act is given the Royal Assent, paving the way for Manitoba to become a Provinces of Canada or province of Canada on July 15.
14th May » The first game of rugby football e.g rugby in New Zealand is played in Nelson, New Zealand known as Nelson between Nelson College and the Nelson Rugby Football Club.
22nd June » US Congress created the United States Department of Justice
26th June » The Christianity e.g Christian holiday of Christmas is declared a federal holiday in the United States.
1st July » The United States Department of Justice formally comes into existence.
15th July » Reconstruction Era of the United States: Georgia (U.S. state) Georgia becomes the last of the former Confederate States of America Confederate states to be readmitted to the Union (American Civil War) Union.
18th July » The First Vatican Council decrees the dogma of papal infallibility.
19th July » Franco-Prussian War: France declares war on Prussia.
6th August » Franco-Prussian War: The Battle of Spicheren is fought, resulting in a Kingdom of Prussia named Prussian victory.
6th August » Franco-Prussian War: The Battle of Wörth (1870) known as Battle of Wörth results in a decisive Kingdom of Prussia or Prussian victory.
8th August » The 'Republic of Ploiești', a failed Liberalism and radicalism in Romania e.g Radical-Liberal rising against Domnitor Carol I of Romania or Carol of Romania.
16th August » Franco-Prussian War: The Battle of Mars-la-Tour is fought, resulting in a Kingdom of Prussia known as Prussian victory.
18th August » Franco-Prussian War: Battle of Gravelotte is fought.
24th August » The Wolseley Expedition reaches Manitoba to end the Red River Rebellion.
1st September » Franco-Prussian War: the Battle of Sedan is fought, resulting in a decisive Kingdom of Prussia known as Prussian victory.
2nd September » Franco-Prussian War: Battle of Sedan Prussian forces take Napoleon III of France and 100,000 of his soldiers prisoner.
3rd September » Franco-Prussian War: The Siege of Metz begins, resulting in a decisive Kingdom of Prussia named Prussian victory on October 23.
4th September » Emperor Napoleon III of France is deposed and the French Third Republic known as Third Republic is declared.
6th September » Louisa Ann Swain of Laramie, Wyoming becomes the first woman in the United States to cast a vote legally after 1807.
18th September » Old Faithful Geyser is observed and named by Henry D. Washburn during the Washburn–Langford–Doane Expedition to Yellowstone.
19th September » Franco-Prussian War: The Siege of Paris (1870–71) e.g Siege of Paris begins, which will result on January 28, 1871 in the surrender of Paris and a decisive Kingdom of Prussia called Prussian victory.
19th September » Having invaded the Papal States a week earlier, the Italian Army lays siege to Rome, entering the city the next day, after which the Pope described himself as a Prisoner in the Vatican.
20th September » 'Bersaglieri' corps capture of Rome known as enter Rome through the 'Porta Pia' and complete the Italian unification known as unification of Italy.
7th October » Franco-Prussian War Siege of Paris (1870-1871) named Siege of Paris: Leon Gambetta flees Paris in a hot-air balloon.
23rd October » Franco-Prussian War: the Siege of Metz concludes with a decisive Kingdom of Prussia known as Prussian victory.
27th October » Marshal François Achille Bazaine surrenders to Kingdom of Prussia Prussian forces at the conclusion of the Siege of Metz (1870) Siege of Metz along with 140,000 France French soldiers in one of the biggest French defeats of the Franco-Prussian War.
1st November » In the United States, the Weather Bureau (later renamed the National Weather Service) makes its first official Meteorology e.g meteorological forecast.
12th December » Joseph H. Rainey of South Carolina becomes the second black Congress of the United States known as U.S. congressman, the first being Hiram Revels.
26th December » The 12.8-km long Fréjus Rail Tunnel through the Alps is completed.