1870s

Technology

• The invention of the telephone (1876) by Alexander Graham Bell.
• The light bulb was invented.
• The phonograph is invented in 1877 by Thomas Edison.

Science

• Ludwig Boltzmann's statistical definition of thermodynamic entropy

War, peace and politics

• Franco-Prussian War (1870–1871) results in the collapse of the Second French Empire and in the formation of both the French Third Republic and the German Empire
• Continuing expansion of the British Empire; beginning of the New Imperialism
• Bulgaria and Romania declare independence following war against Turkey

Other

• In the United States, continuation of post-Civil War reconstruction until its conclusion under President Rutherford B. Hayes in 1877