How did Social Darwinists justify expansion? Survival of the fittest resulted in strong nations controlling weaker ones.
The success of the American economy relied on new markets abroad.
American expansion created stability in regions such as Latin America.

Social Darwinists believe in “survival of the fittest”—the idea that certain people become powerful in society because they are innately better. Social Darwinism has been used to justify imperialism, racism, eugenics and social inequality at various times over the past century and a half.