What was one of the core beliefs of American imperialism during the late 19th and early 20th centuries?

One of the core beliefs of American imperialism during the late 19th and early 20th centuries was the belief in American exceptionalism. This concept held that the United States was distinct from other nations due to its unique values, democratic ideals, and the perceived duty to spread these qualities globally. Many Americans believed that their nation was destined to expand its influence and territory, which supported the idea that they had a responsibility to promote civilization, democracy, and capitalism in other regions, particularly in places like the Philippines, Puerto Rico, and Guam.

This belief in exceptionalism also contributed to the justification of imperialistic actions as a means of uplifting "lesser" societies and spreading American culture. The perspective shaped public opinion and policy, advocating for a stronger international presence and engagement in global affairs, which was a prominent aspect of U.S. actions during this era.