西せい漸ぜん運うん動どう

noun

Westward movement; westward expansion of the United States

Historical term referring to the 19th-century expansion of U.S. territory westward across North America.

• アメリカ史しの授じゅ業ぎょうで西せい漸ぜん運うん動どうについて学まなんだ。

  I learned about the Westward movement in American history class.