Oh brother, I didn't realize you guys were so ignorant of the history of your own country lol.

Most scholars held these lower estimates as factual until the 1960s, when anthropologist Henry Dobyns published research applying historical and archaeological data to assert a far higher pre-Columbian population of possibly over 100 million

https://en.wikipedia.org/wiki/Population_history_of_the_Indigenous_peoples_of_the_Americas