After the establishment of the first American settlement at Jamestown, Virginia, in 1607, the United States embarked on a mission of westward expansion. Click on the map below to watch the United States as it grows westward.

This map represents the changes in boundaries from the 18th to 19th centuries and the acquisitions that eventually formed the United States. Review the map again. There are territories that were ceded or a part of a cession, meaning the territory was granted to the United States by another country.

→ Think about this - Do you think acquiring territories to form the United States was peaceful? Why or why not? What evidence from the map supports your answer?

Take a look at the southwestern region of the United States. Much of the expansion in that area was due, in part, to events resulting from the relationship between the United States and Mexico. In this lesson, you will learn how the war with Mexico helped the United States to follow the idea of manifest destiny and expand its borders to the Pacific Coast.