Worldmapper has a nice interactive tool that allows you to visualize lots of demographic data
A recent find by archaeologists put the first north Asians in North America 30,000 years ago.
The weird thing is that they used weapons made of ivory - in Siberia.
There used to be wooly rhinoceroses up there, you know.
The main European influx came after 1492, but most know of the Vikings centuries earlier.
It's interesting to actually read the sagas of Erik the Red.