It's interesting that the word "pop" originated in England, first documented trace of it being 1812. But then it has become such a U.S. regional term that many are even puzzled by its use!
From Online Etymology Dictionary: Meaning "flavored carbonated beverage" is from 1812.
"A new manufactory of a nectar, between soda-water and ginger-beer, and called pop, because ‘pop goes the cork’ when it is drawn." [Southey, letter, 1812]
I guess if they had not used corks, but went with metal bottle caps and poptop cans from the start, we'd now be calling "Pop" either ""Hiss" or maybe "Woosh".