Polk believed that it was the destiny of the U.S. to expand
entire continent as part of its Manifest Destiny. He believed that the war with
Mexico fitted well with that vision.
When the U.S. won it took over several territories from the Mexicans.
Answer:
How is organizing the past by region similar to or different from organizing the past by period? ... A historian who organizes the past by region focuses on a big idea that occurs across history, whereas a historian who organizes the past by period focuses on a specific area of the world.
