The very first mocktail, as far as we know, was the Shirley Temple,
named after Shirley Temple. According to legend, a bartender made it
up to serve to the innocent Miss Temple during the raging Hollywood
parties of the 1930s. This Shirley Temple is made of club soda (or
lemon-lime soda,) ice, grenadine, and a maraschino cherry on top.

Via makesandtakes.com