According to Wikipedia: "In 1905 in San Francisco, 11-year-old Frank Epperson was mixing powdered flavoring for soda and water out on the porch. He left it there, with a stirring stick still in it. That night, temperatures reached a record low, and the next morning, the boy discovered the drink had frozen to the stick, inspiring the idea of a fruit-flavored 'Popsicle'. Eighteen years later in 1923, Epperson introduced frozen pop on a stick to the public at Neptune Beach, an amusement park in Alameda, California. Seeing that it was a success, in 1924 Epperson applied for a patent for his "frozen confectionery" which he called "the Epsicle ice pop". He renamed it to Popsicle, allegedly at the insistence of his children."
More fun facts at the Popsicle website. For example, I didn't know the double popsicles were introduced during the Great Depression, so two kids can share popsicles together for a nickel.
The following ice pops were made by Pippaloo. The ice pops look almost translucent like real ice.