1. Westward ExpansionUnit 9 Matt H. Trey R. Haley W. James A.

2. Manifest Destiny Was the idea that Unites States should expand to the 54 40 line and out to the pacific ocean

3. James Polk Our President

4. Oregon country

5. How did the idea of Manifest Destiny help bring about the expansion of the United States? Because our president James Polk wanted our state to expand towards the 54 40 line. But what he did was Great Britain gave up the Oregon country and in exchange they told us to only expand to the 49 line. Then our state was complete.