Which ideology justified the annexation of western territories in the 19th century?

• A. Social Darwinism
• B. Manifest Destiny
• C. Isolationism
• D. Realism

Answer: (B)

Manifest Destiny is the ideology that justified the annexation of western territories in the 19th century. This belief held that it was the obvious fate and duty of the United States to expand its territory across the North American continent, promoting not only the physical growth of the nation but also the spread of democracy and civilization. Proponents of Manifest Destiny perceived this expansion as an inevitable and beneficial process, essential to the nation’s destiny.

This ideology fueled actions such as the annexation of Texas, the Oregon Trail migration, and the Mexican-American War, all of which contributed to the territorial growth of the United States during this period. The notion of Manifest Destiny was deeply intertwined with American nationalism and was often accompanied by a belief in the racial and cultural superiority of Anglo-Americans, further justifying westward expansion in the eyes of many citizens at the time.