Imperialism refers to ruling over other peoples or territories through military dominance, economic power, or colonization. In the mid-to-late 1800s, European powers divided up Asia and Africa among themselves as they aggressively expanded their colonial empires. Driven by desires for raw materials, new markets, and strategic ports, as well as nationalism and social pressures, European nations and the United States engaged in imperialism in Africa and Asia during this period, exploring and colonizing many regions. While imperialism brought some benefits like technology and infrastructure to colonized peoples, it also exploited them through practices like cheap labor and denied local populations their freedom and self-determination.