A physical map shows the landscape of an area. This map can help explain the historical development of a country because over time, it will show differences in the physical marks of an area that are made by human impact. For example, if a large forest is cleared out to create a highway, there will be a difference in the physical map before and after the forest is cleared out. In regard to the United States, the physical map of the country would change over time from the right side of the country to the left as the population continued moving westward. In this way, we can track the historical development of a country.
