a large region of land

to add or incorporate (a new territory) into a country

something that is gained, or acquired. The united states made a number of land acquisitions between 1783 and 1853 to reach the west coast.

on american belief in the 1800s that it was the natural right of the united States to expand westward to the pacific ocean

an area of land set aside by the U.S government for american Indians to live on

a group of people sent to explore unknown places

the geographic line between two places, such as two countries

to give up territory, usually as a result of a treaty