According to The Popcorn Book that I think I bought from Scholastic at least 24 years ago:

"Popcorn is the oldest of three main types of corn...was discovered by the Indian
people in the Americas many thousands of years ago...But popcorn is even older
than that. In a bat cave in New Mexico, archeologists found some popped corn that
was 5,600 years old...And 1000-year-old popcorn kernels were found in Peru that
could still be popped."

I've read if stored corn won't pop put it in a jar in the fridge with a tablespoon of water, then try again in a few days.