Industrialized nations like European powers, the United States, Russia, and later Japan strengthened control over their colonies and established overseas empires in Asia, Africa, and the Pacific between the 18th-19th centuries. They did so to gain profits from trade, capture markets for factory goods, absorb excess population, and achieve national prestige. Imperialism involved exploiting weaker nations' resources and asserting the dominance of European races through the ideology of social Darwinism. Colonizers used military might, alliances with local elites, and economic coercion to partition and dominate Africa and Asia.