April 30 - The Camp Grant Massacre takes place in Arizona Territory.
May 4 - The National Association, the first professional baseball league, opens its first season in Fort Wayne, Indiana.
May 21 - French troops invade the Paris Commune and engage its residents in street fighting. By the close of "Bloody Week" some 20,000 communards have been killed and 38,000 arrested.
May 22 - The U.S. Army issued an order for abandonment of Fort Kearny in Nebraska.
June 10 - Sinmiyangyo: Captain McLane Tilton leads 109 Marines in naval attack on Han River forts on Kanghwa Island, Korea.
June 13 - In Labrador, a hurricane kills 300 people.
June 16 - The University Tests Act allows students to enter the Universities of Oxford, Cambridge and Durham without religious tests, except for courses in theology.
July 2 - Victor Emmanuel II of Italy enters Rome after its conquest from the Papal States.
July 20 - British Columbia joins the confederation of Canada.
July 30 - The Staten Island Ferry Westfield's boiler explodes, killing over 85 people.
September 20 - Bishop John Coleridge Patteson martyred on the island of Nukapu, a Polynesian outlier island now in the Temotu province of the Solomon Islands. He was the first bishop of Melanesia.
October 8 - Four major fires break out on the shores of Lake Michigan in Chicago, Peshtigo, Wisconsin, Holland, Michigan, and Manistee, Michigan. The Great Chicago Fire is the most famous of these, leaving nearly 100,000 people homeless, although the Peshtigo Fire killed as many as 2,500 people making it the deadliest fire in United States history.
October 9 - The Great Chicago Fire is brought under control.
November 10 - Henry Morton Stanley locates missing explorer and missionary, Dr. David Livingstone in Ujiji, near Lake Tanganyika, allegedly greeting him with the words, "Dr. Livingstone, I presume?"
November 17 - The National Rifle Association is granted a charter by the state of New York.
December 26 - Gilbert and Sullivan collaborate for the first time, on their lost opera, Thespis. It does modestly well, but the two would not collaborate again for four years.
