- 1900 to 1909 1910 to 1919 1920 to 1929
- 1930 to 1939 1940 to 1949 1950 to 1959
- 1960 to 1969 1970 to 1979 1980 to 1989
- 1990 to 1999 2000 onwards
1920
- The tommy gun patented by John T Thompson.
- The Band-Aid (pronounced 'ban-'dade) invented by Earle Dickson.
1921
- Artificial life begins -- the first robot built.
- John Larson invented the lie detector.
1922
- Insulin invented by Sir Frederick Grant Banting.
- The first 3-D movie (spectacles with one red and one green lens) is released.
1923
- Garrett A. Morgan invents a traffic signal.
- The television or iconoscope (cathode-ray tube) invented by Vladimir Kosma Zworykin.
- John Harwood invented the self-winding watch.
- Clarence Birdseye invents frozen food.
1924
- The dynamic loudspeaker invented by Rice and Kellogg.
- Notebooks with spiral bindings invented.
1925
- The mechanical television a precursor to the modern television, invented by John Logie Baird.
1926
- Robert H. Goddard invents liquid-fueled rockets.
1927
- Eduard Haas III invents PEZ candy.
- JWA Morrison invents the first quartz crystal watch.
- Philo Taylor Farnsworth invents a complete electronic TV system.
- Technicolor invented.
- Erik Rotheim patents an aerosol can.
- Warren Marrison developed the first quartz clock.
- Philip Drinker invents the iron lung.
1928
- Scottish biologist Alexander Fleming discovers penicillin.
- Bubble gum invented by Walter E. Diemer.
- Jacob Schick patented the electric shaver.
1929
- American, Paul Galvin invents the car radio.
- Yo-Yo re-invented as an American fad.
