I was reading through one of those Reddit posts asking about little known facts and someone mentioned that there was a great empire in North America that came before most of the well known Native American tribes. Apparently, according to the comment, there was some type of huge event that wiped the empire out and gave rise to the nomadic North America. Can anyone elaborate on this?
edit: this would have been well before any European colonization
I am not aware of any "major" empires in North America that are well documented and resemble those of Eurasia (e.g. the Roman Empire), but you may have heard a muddled reference to Mississippian Culture which had declined by the time of the arrival of large numbers of Europeans to the area. There is speculation that the wave of diseases that arrived with European contact wiped them out, but I'm not sure if that claim is actually sufficiently supported by evidence, or if it is possible that their society was undergoing a collapse and the arrival of Europeans simply coincided with that moment.
That is more or less the story of the Nephites in the Book of Mormon. I can't think of any real "Empires" that would fit that description, except perhaps the Chacoan or Mesa Verde cultures of Northwest New Mexico, which have been popularly described as empires. Do you have more information or perhaps a link to the original comment?