1920's Inventions By kimberrrrrly May 5, 1920 Traffic lights were invented. Jul 30, 1920 Automobile with Combustion Engine Jul 30, 1921 Insulin Apr 15, 1923 Bulldozer Dec 14, 1926 Liquid-Fueled Rocket Jun 21, 1927 Kool-Aid The original name was Fruit Smack Jul 10, 1927 PEZ Candy Jul 24, 1927 Bread Slicer Oct 28, 1928 Bubble Gum Apr 30, 1929 Car Radio
