The process of acquiring and settling new land in the western regions of the United States, such as the Louisiana Purchase and the Mexican Cession. This led to an increase in territory for the nation.
Related terms
Manifest Destiny: The belief that it was America's destiny to expand its territory from coast to coast.
Homestead Act: A law that provided free land to settlers willing to develop and live on it for a certain period of time.
Oregon Trail: A famous route used by pioneers traveling westward during the 19th century.