Which ideology justified U.S. expansion during the late 19th century?

The ideology that justified U.S. expansion during the late 19th century is Manifest Destiny. This belief was rooted in the idea that it was a divine right and destiny of the United States to expand its territory across the North American continent, and it evolved to include overseas territories as well.

Manifest Destiny held that the U.S. was destined to spread democracy and capitalism, which was seen as a benevolent mission to civilize and uplift other nations and peoples. This ideology fueled the justification for actions such as the annexation of territories and involvement in foreign conflicts, as proponents argued that expansion was not only beneficial but necessary for the nation's growth and prosperity.

While Social Darwinism also influenced some perspectives during this time, specifically in justifying imperialist actions based on perceived racial and cultural superiority, it did not serve as the primary ideological justification for expansion itself. Isolationism runs counter to the ideas of expansion, advocating more for staying out of foreign entanglements. Marxism, focusing on class struggle and economic systems, did not provide a rationale for territorial expansion in the same way.

Thus, Manifest Destiny, with its emphasis on a predetermined role for the U.S. in spreading its values and governance, stands out as the central ideology that supported the nation's imperial