Final answer:
American opinion shifted in the 1880s towards making the U.S. a world power due to industrialization, which spurred economic growth, and nationalism, which fostered a desire to compete with European powers and extend American influence through imperialism.
Step-by-step explanation:
In the 1880s, American opinion began to shift towards making the U.S. a world power, largely due to two key factors: industrialization and nationalism. The rapid expansion of industry increased the economic size of the U.S. and fueled urban growth, leading to a nationalistic desire to expand American influence and to compete with European empires. This was coupled with large-scale immigration, contributing to the country’s workforce and further economic growth. The seductive notion of imperialism, with the promise of political, economic, and military control over other territories, also played a critical role in driving the United States away from isolationism toward expansion-mindedness and the desire to become a world power.