Final answer:
America's expansionism in the late 1800s was influenced by demographic growth, the search for cheap land, political motivations to prevent British occupation, and economic factors such as finding new markets for factory-produced goods and dominating trade routes with Asia.
Step-by-step explanation:
The policy of expansionism or imperialism that America followed in the late 1800s was driven by a variety of demographic, economic, and political reasons. As the population grew rapidly, Americans sought more land due to declining soil fertility in the Eastern farms and the promise of cheap land in the West. Politically, expansionism was seen as a means to assert U.S. dominance and prevent British occupation of western territories, while preserving the republic rooted in Jefferson’s ideals. Economically, the expansionism policy was motivated by the need to find new markets for its goods, particularly as factory production increased and the quantity of goods surpassed domestic consumption. Eastern merchants also wanted control of West Coast ports to enable trade with Asia. This juxtaposition of domestic and international ambitions made expansionism an attractive and rational approach for the United States.