Nobody invented popcorn; it has been around for thousands of years. In fact, popcorn was probably the first type of wild corn eaten by humans. It was also the first type of corn to be domesticated, which the Pre-Columbian people did in 5000 B.C.
When Europeans first came to the New World, they found that popcorn played an important role in Aztec ceremonies, as well as in their diet. Popcorn became a very popular snack during the 1800s after advances in agricultural technology made it possible to cultivate it in the American South and Midwest. It was during this time the name "popcorn" was coined.