The Great Inventions in the 20th Century

These "Group of Five" inventions led to the golden age of U.S. productivity growth from 1913-1972

Group I: Electricity

• Revolutionized manufacturing by decentralizing source of power, enabled flexible and portable tools and machine
• Automated consumer appliances: laundry machine, refrigeration, air conditioning

Group II: Internal Combustion Engine

• Enable personal autos, motor transport, air transport
• Derivative inventions: suburb, highway, supermarket

Group III: Petroleum, Natural Gas, and Molecular processes (chemicals, plastics, pharmaceuticals)

• Reduced air polution (e.g. coal), enabled new & improved materials/products, prolonged life

Group IV: Entertainment, Communication, and Information Innovations

• Made the world smaller
• Telegraph (1844), telephone (1876), phonograph (1877), popular photography (1880s-1890s), radio (1899), motion pictures (1881-1888), television (1911)

Group V: Indoor plumbing, urban sanitation infrastructure, germ theory

• Credited for the great decline in mortality in the four decades prior to World War I, before the invention of antibiotics.

Sources:

Bunch, Bryan and Alexander Hellemans. 1993. The Timetables of Technology: A Chronology of the Most Important People and Events in the History of Technology. New York: Touchstone.

National Academic of Engineering. 2000. Greatest Engineering Achievements of the 20th Century.