Before the European immigration, in the 1400/1500's. All I know is Native Americans lived there, but I don't know how they arrived there. Did they immigrate from somewhere else?
Hi, a related question came in last week, so check out /u/Reedstilt's answer here
And there are some older, more in-depth threads here
Where did American (North) Aboriginals originate from? Did South American Aboriginals originate from the same place? - featuring /u/Reedstilt
Clovis culture and the first people in America - featuring /u/RioAbajo, /u/retarredroof, /u/archaeofieldtech, and /u/Reedstilt
In the settlement of Monte Verde, how did the people get there? - featuring /u/Reedstilt, /u/retarredroof, and /u/girlscout-cookies
Why weren't modern Siberians colonizing the new world prior to Europeans