Around 800 AD, the Maya civilization in Central America collapsed, mostly likely due to climate change caused by volcanic eruptions. Nobody knew where they went, so it was theorized they died out.
When Maya ruins were first discovered by Europeans in the 1800s, many immediately saw cultural similarities between them and North American natives. But no evidence of a migration.
Ruins discovered in Georgia suggest a possible connection between the Maya and the natives of the Southeastern United States. The ruins align with Maya building practices and suggest the Maya middle and lower classes migrated north to escape the drought. They build towns and eventually became absorbed into local societies.
It’s an intriguing and controversial theory. Learn more here at MysteriousEarth.net.