20. Which ideology was often used to justify U.S imperialism in the late 19th century? A) Marxism B) Social Darwinism C) Progressivism D) Populism

The ideology often used to justify U.S. imperialism in the late 19th century was:<br /><br />B) Social Darwinism<br /><br />Social Darwinism applied the concept of "survival of the fittest" from Charles Darwin's theory of evolution to human societies, suggesting that certain nations or races were naturally superior and destined to dominate others. This ideology was used to rationalize expansionist policies and imperialism.