Journalist Henry Morton Stanley begins his famous search through Africa for the missing British explorer Dr. David Livingstone.

With passage of the Third Force Act, popularly known as the Ku Klux Act, Congress authorizes President Ulysses S. Grant to declare martial law, impose heavy penalties against terrorist organizations and use military force to suppress the Ku Klux Klan (KKK).

The humiliating defeat of Louis Napoleon’s Second Empire of France is made complete on May 10, 1871, when the Treaty of Frankfurt is signed, ending the Franco-Prussian War and marking the decisive entry of a newly unified German state on the stage of European power politics, so long dominated by the great empires of England and France.

The Kiowa Chief Satanta joins with other Native Americans to massacre a wagon train near the Red River in northeastern Texas.

John Wesley Hardin, one of the deadliest men in the history of the Old West, arrives in Abilene, Kansas, where he briefly becomes friends with Marshal Wild Bill Hickok.

On October 8, 1871, flames spark in the Chicago barn of Patrick and Catherine O’Leary, igniting a two-day blaze that kills between 200 and 300 people, destroys 17,450 buildings, leaves 100,000 homeless and causes an estimated $200 million (in 1871 dollars; more than $4 billion today) in damages.

On October 8, 1871, the Peshtigo Fire, now considered the most devastating fire in United States history, burns in Wisconsin. Some 1,200 people lost their lives and 2 billion trees were consumed by flames. Despite the massive scale of the blaze, it was overshadowed by the Great Chicago Fire, which began later that night about 250 miles away.