where did the first societies in north america come from
History of North America The specifics of Paleo-Indians' migration to and throughout the Americas, including the exact dates and routes traveled, are subject to ongoing research and discussion.[1] For years, the traditional theory has been that these early migrants moved into the Beringia land bridge between eastern Siberia and present-day Alaska around 40,000 â€“ 17,000 years ago, when sea levels were significantly lowered due to the Quaternary glaciation.[1][4] These people are believed to have followed herds of now-extinct pleistocene megafauna along ice-free corridors that stretched between the Laurentide and Cordilleran ice sheets.[5] Another route proposed is that, either on foot or using primitive boats, they migrated down the Pacific coast to South America.[6] Evidence of the latter would since have been covered by a sea level rise of hundreds of meters following the last ice age.[7]