Answer:
I accept that James K. Polk was the smart and perfect leader who extended the state and borders of the United States. "Manifest Destiny" played a large role in that. "Manifest Destiny" was this feeling that ruled at American living within that 1840s where Americans thought that they were pre-ordained to extend that regional edges of the USA from the Atlantic to the Pacific Ocean and from Canada to the Rio Grande River. In the essay you one can see why James K. Polk was a smart and visionary human.