Slurpees
Dairy Queen owner Omar Knedlik had a broken soda machine. So one day in the late 1950s, he put a few bottles of soda in the freezer resulting in a frozen slushy-like drink. People loved it and started specifically asking for that frozen drink.
He eventually built his own machine to combine and freeze a flavor mix, water, and carbon dioxide before his product was sold to convenience stores and eventually, 7-Eleven.
