Americans who supported manifest destiny primarily believed that the united states should acquire colonies in other parts of the world. develop the nation’s existing territory. spread across the continent to the pacific ocean. share territory peacefully with american indians.

Americans who supported Manifest Destiny primarily believed that the United States should spread across the continent to the Pacific Ocean (Option 3).

The concept of "Manifest Destiny" was developed in the mid-1800s, by Americans who believed that the United States had a God-given right and duty to spread their dominion across the continent to the Pacific Ocean.

This concept was mainly based in the belief that American people and their institutions had special virtues and potentialities, and therefore they had a duty to spread these institutions to redeem and remake the world in the image of the U.S., which was a high example; and that such task was given and protected by God.

answer; i believe the correct answer is (the willamete valley);