美国历史概况

第一部分 CHAPTER 1: Early AmericaAn Outline of American History "Heaven and Earth never agreed better to frame a place for man's habitation." 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 contained 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 bee