1. Pre-Columbian era
A. The first Americans - at
the height of the Ice Age, between 34,000 and 30,000 B.C., much of the world’s
water was locked up in vast continental ice sheets. As a result, the Bering Sea
was hundreds of meters below its current level, and a land bridge, known as
Beringia, emerged between Asia and North America. At its peak, Beringia is
thought to have been some 1,500 kilometers wide. A moist and treeless tundra,
it was covered with grasses and plant life, attracting the large animals that
early humans hunted for their survival.