Young Frank Epperson left a glass of soda water powder and water outside in his back porch with a wooden mixing stick in it. That night the temperature dropped below freezing, and when Epperson returned to the drink the next morning, he found that the soda water had frozen inside the glass. He then ate what is the first recorded ice pop.
This is actually a case of serendipity (or fortuitous discovery).

Seventeen years later, Epperson became the first to put “frozen ice on a stick” on the market.