Chapter 1 New World Beginnings 33,000 B.C. - A.D. 1769 225 Million Years Ago - Pangaea started to break apart. 10 Million Years Ago - North America was shaped by nature - Canadian Shield 2 Million Years Ago- Great Ice Age 35,000 Years Ago - The oceans were glaciers and the sea level dropped, leaving an isthmus connecting Asia and North America. The Bering Isthmus was crossed by people going into North America. 10,000 Years Ago - Ice started to retreat and melt, raising the sea levels and covering up the Bering Isthmus. Peopling the Americas Evidence suggests that early people may have come to the Americas in crude boats, or across the Bering Isthmus. By the time Columbus arrived in America in 1492, over 54 million people may have been living in North & South America.