Welcome to the United States of America, located between Canada and Mexico and between the Atlantic Ocean and the Pacific Ocean. The United States was originally settled by Native American peoples, and European settlers did not arrive until a few hundred years ago. That might sound like a long time, but it's nothing if you think like a geographer! People have come from all over the globe to work, study, and live here. The United States is the third-biggest country in the world in terms of land mass. Only Russia and Canada have more land. It also has the third-largest population in the world; only China and India have more people.

In this chapter you will learn about the states, the regions, and the landscapes that make up this great nation. You'll find out why the Appalachian Mountains aren't as high as the Rocky Mountains, what gave the Rockies their sharp peaks, and how the Great Plains got to be so flat. You'll also discover how different climates and terrains have shaped each region of the country. Let's hit the highway for a road trip around the U.S.A., from sea to shining sea!