1870s

alt=|thumb|335x335px|From left to right, clockwise: Conflicts start to increase between the Second French Empire and the [[Kingdom of Prussia leading to the Franco-Prussian War in 1870; a fire in Chicago kills approximately 300 people and leaves about another 100,000 people homeless in 1871; Claude Monet's Impression, Sunrise is recognized as the source of inspiration for the Impressionist movement; The U.S. Army is defeated by Arapaho, Lakota and Northern Cheyenne tribes during the Battle of the Little Bighorn in 1876; Nicolaus Otto patents the first commercial four-stroke internal combustion