1870 CE
A year defined by the outbreak of the Franco-Prussian War, Rome's annexation as the capital of a unified Italy, and the ratification of the Fifteenth Amendment to the United States Constitution.
Geopolitics & Diplomacy
- France declared war on Prussia on July 19, beginning the Franco-Prussian War after a diplomatic crisis over the candidacy of a Hohenzollern prince for the Spanish throne.
- Italian troops entered Rome on September 20 through a breach at Porta Pia, completing the unification of Italy and ending the temporal power of the papacy.
- The Fifteenth Amendment to the United States Constitution was ratified on February 3, prohibiting the denial of voting rights based on race, color, or previous condition of servitude.
- The Ems Dispatch, edited by Otto von Bismarck to appear provocative, was published on July 13, inflaming French public opinion and hastening the declaration of war.
- Napoleon III of France surrendered to Prussian forces at the Battle of Sedan on September 2, leading to his capture and the collapse of the Second French Empire.
- The Third French Republic was proclaimed on September 4 after news of Napoleon III's capture reached Paris, ending the Second Empire.
- Spain adopted a new constitution establishing a constitutional monarchy, and the Cortes elected Amadeo of Savoy as king in November.
- The British colony of Manitoba was established on July 15 as a province of Canada following the Red River Resistance.
- The United States Senate rejected the proposed annexation of the Dominican Republic despite President Ulysses Grant's support for the measure.
- The Naturalization Act of 1870 extended United States citizenship rights to persons of African descent for the first time.
Conflict & Security
- The French garrison at Strasbourg surrendered on September 28 after a prolonged Prussian bombardment, giving Germany control of the strategically important Alsatian capital.
- The Siege of Paris began on September 19 as Prussian and German allied forces encircled the French capital, cutting it off from the rest of the country.
- The Battle of Mars-la-Tour on August 16 saw Prussian forces block the retreat of the French Army of the Rhine toward Verdun despite being heavily outnumbered.
- The Battle of Gravelotte on August 18 was the largest battle of the Franco-Prussian War, with combined casualties exceeding 30,000.
- French forces under Marshal Bazaine were besieged at Metz beginning in August and would remain trapped there for months.
- The Red River Resistance in Canada ended when Colonel Garnet Wolseley led a military expedition to the Red River Settlement, arriving in August to find Louis Riel had fled.
- Fenian raids from the United States into Canada occurred again in May, with Irish republican militants crossing the border into Quebec before being repelled by Canadian forces.
- The Ku Klux Klan and other white supremacist organizations carried out widespread violence against Black voters and Republican officeholders across the American South.
- Parisians organized a Government of National Defense to continue the war against Prussia after the fall of Napoleon III.
- The French naval blockade of Prussian ports proved largely ineffective due to the limited reach of the French fleet in the North Sea and Baltic.
Economy & Finance
- The Franco-Prussian War disrupted European trade and finance, causing sharp declines on the Paris Bourse and uncertainty in European capital markets.
- The Suez Canal, opened the previous year, carried its first full year of traffic, significantly reducing shipping times between Europe and Asia.
- The Standard Oil Company was incorporated in Ohio by John D. Rockefeller and his associates on January 10, beginning the consolidation of the American petroleum industry.
- Construction of the transcontinental railroad network in the United States continued with new lines extending into the western territories.
- The Siege of Paris caused severe food shortages, with residents resorting to eating horses, cats, dogs, and zoo animals as supplies ran out.
- Japan's first railway was under construction between Tokyo and Yokohama with British engineering expertise and financing.
- The global cotton trade was reshaped as Indian and Egyptian cotton production expanded to fill gaps left by the American Civil War's disruption of Southern output.
- German industrial production continued to grow rapidly, with coal and steel output increasing as the Ruhr Valley industrialized.
- The first boardwalk in the United States was constructed in Atlantic City, New Jersey, to keep sand out of the resort hotels.
- The Department of Justice was established by the United States Congress on July 1, creating a federal department to handle legal matters for the government.
Technology & Infrastructure
- Construction began on the Brooklyn Bridge, designed by John Augustus Roebling, connecting Manhattan and Brooklyn across the East River.
- The celluloid manufacturing process was patented by John Wesley Hyatt, providing a commercially viable early plastic material.
- The Parisians used hot air balloons to carry mail and passengers out of the besieged city, with over sixty balloon flights made during the siege.
- The pneumatic tube postal delivery system was expanded in London, using compressed air to send mail between post offices.
- Thomas Edison opened his first industrial research laboratory in Newark, New Jersey, employing a team of machinists and experimenters.
- The French mitrailleuse, an early rapid-fire weapon, was deployed in battle during the Franco-Prussian War but proved less effective than anticipated.
- The Prussian army made extensive use of the railroad system for rapid troop mobilization and supply, giving them a decisive logistical advantage over France.
- The stock ticker, improved by Thomas Edison, became widely used on Wall Street, allowing rapid transmission of stock prices.
- Telegraph communication played a critical role in the Franco-Prussian War, enabling rapid coordination of military operations.
- The rotary press continued to transform newspaper production, enabling mass printing and wider distribution of daily papers.
Science & Discovery
- The periodic table of elements was further refined by Dmitri Mendeleev, who predicted the existence of several undiscovered elements based on gaps in his table.
- Dmitri Mendeleev continued refining his periodic table of the elements, successfully predicting the properties of undiscovered elements including gallium, scandium, and germanium.
- The Kekulé benzene conference was held in Berlin, solidifying August Kekulé's ring structure model of benzene as widely accepted in organic chemistry.
- The Meteorological Office in Britain began issuing daily weather forecasts for the public based on telegraph-transmitted observations.
- Benjamin Apthorp Gould published Uranometria Argentina, a comprehensive star catalog of the southern hemisphere observed from Cordoba, Argentina.
- Ernst Haeckel's studies of marine organisms continued to advance understanding of biological classification and evolutionary morphology.
- Rudolf Clausius published a major paper further developing the second law of thermodynamics and the concept of entropy.
- The French mathematician Camille Jordan published his Traité des substitutions, a foundational text in group theory and abstract algebra.
- Archaeological excavations led by Heinrich Schliemann began at Hissarlik in the Ottoman Empire, the site he identified as ancient Troy.
- Louis Pasteur and Robert Koch independently advanced the germ theory of disease through their research on microbial pathogens.
Health & Medicine
- Smallpox epidemics continued to devastate populations in Europe and North America, with a major outbreak spreading through France during the war.
- The Franco-Prussian War caused massive casualties from battlefield injuries, and poor sanitary conditions in military camps led to outbreaks of typhus and dysentery.
- Joseph Lister's antiseptic surgical methods gained wider acceptance in Britain and parts of Europe, reducing postoperative infection rates.
- The besieged population of Paris suffered from malnutrition and disease during the winter months as food supplies were exhausted.
- Cholera remained a persistent public health threat in European cities, particularly in densely populated urban areas with poor sanitation.
- The American Red Cross had not yet been founded, but Clara Barton traveled to Europe to observe the work of the International Red Cross during the Franco-Prussian War.
- Yellow fever outbreaks continued in the southern United States and the Caribbean, with the disease's mode of transmission still unknown.
- Infant mortality remained extremely high throughout the industrialized world, with waterborne diseases a leading cause of death in children.
- The use of chloroform and ether as anesthetics became standard practice in surgical operations across Europe and North America.
- Mental illness was treated primarily through institutionalization in asylums, where conditions were often harsh and therapeutic approaches minimal.
Climate & Environment
- Atmospheric carbon dioxide concentration was approximately 288 parts per million, as later confirmed by ice core analysis.
- A devastating flood struck Rome in December, with the Tiber River overflowing its banks and inundating large parts of the newly designated Italian capital.
- Deforestation accelerated in the American Midwest and Great Plains as settlers converted prairies and forests to farmland.
- The Franco-Prussian War caused widespread environmental damage in northeastern France, with battles destroying farmland, forests, and villages.
- Severe drought conditions affected parts of India, contributing to crop failures and food shortages in several regions.
- Whaling operations in the Arctic and Antarctic continued to deplete whale populations, with petroleum beginning to replace whale oil for lighting.
- The passenger pigeon population in North America continued to decline due to commercial hunting and habitat loss.
- Coal burning expanded rapidly in industrial cities across Europe and North America, worsening urban air pollution.
- The American bison population continued to be decimated by commercial hunting on the Great Plains.
- Volcanic eruptions in Iceland and the Mediterranean were recorded, though none caused globally significant climate effects.
Culture & Society
- Jules Verne published Twenty Thousand Leagues Under the Sea, captivating readers with its vision of undersea exploration.
- Charles Dickens died on June 9, leaving his final novel, The Mystery of Edwin Drood, unfinished.
- Leo Tolstoy was at work on Anna Karenina, which he would begin serializing in 1873.
- Richard Wagner's opera Die Walküre premiered in Munich on June 26 as the second installment of the Ring cycle.
- The first women's suffrage organization in France was established during the siege of Paris, advocating for women's right to vote.
- The Metropolitan Museum of Art was incorporated in New York on April 13, laying the foundation for one of the world's largest art museums.
- The game of rugby was codified with formal rules by the Rugby Football Union, which would be officially founded the following year.
- The Young Women's Christian Association expanded its activities in the United States, providing housing and support services for women in cities.
- The world population was approximately 1.411 billion.
- The first Greek-letter sorority, Kappa Alpha Theta, was founded at Indiana Asbury University on January 27.