Ap U.S. History Notes

Page 1 of 11

Ap U.S. History Notes

By | November 2012
Page 1 of 11
New World Beginnings

I. The Shaping of North America
a. Continents Form
i. 225 million years ago, a single supercontinent contained all the world’s dry land ii. Enormous chunks of terrain began to drift away from this supercontinent. This had the following results: 1. Opened the Atlantic and Indian Oceans 2. Narrowed the Pacific Ocean

3. Formed the landmasses of Eurasia, Africa, Australia, Antarctica, and the Americas iii. The existence of a single original continent has been proved in part by the discovery of nearly identical species of fish that swim today in the long-separated freshwater lakes of the various continents b. Mountain Ranges

i. Shifting and folding of the earth’s crust thrust up mountain ranges 1. 350 million years ago – Appalachians 2. 135-25 million years ago – Rockies, Sierra Nevada, Cascades c. Ice Age

i. Occurred 2 million years ago
ii. Ice sheets crept from the polar regions to blanket parts of Europe, Asia, and the Americas iii. In North America, the glaciers covered most of present-day Canada and the U.S. as far southward as Pennsylvania, Ohio, the Dakotas, and the Pacific Northwest iv. When the glaciers retreated about 10,000 years ago, they left the North American landscape much as we know it today 1. Melting glaciers formed the Great Lakes 2. They drained southward through the Mississippi River into the Gulf of Mexico 3. Melting glaciers left the Great Salt Lake II. Peopling the Americas

a. Bering Land Bridge
i. As the Ice Age was ending and the sea level dropped, it exposed a land bridge connecting Eurasia with North America in the area of the present-day Bering Sea between Siberia and Alaska ii....