The tremendous changes that industrialism and urbanization brought triggered a debate over how best to address society's problems. Some Americans embraced the ideas of individualism and Social Darwinism.
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In fact, industry had made the U.S. the richest nation in the world at this time. The Second Industrial Revolution caused growth in industry and transportation, which allowed increased trade between nations. Combined with a merchant marine capable of transporting goods by sea, a world economy began to form.