In the 1860s and early 1870s, the U.S. focused primarily on domestic issues: Reconstruction, settlement of the American West, and industrialization. Apart from acquiring Alaska from Russia in 1867, the U.S. achieved little in the area of foreign expansion. But as the American factory system developed and industrial output soared, the nation began to look abroad with new interest, because, as a rising industrial power, the U.S. needed to find foreign markets in which to sell its manufactured products and from which to acquire raw goods. Initially, the policy that the U.S. pursued to meet its growing economic needs was one of expansionism rather than imperialism. Instead of imposing a military presence and colonial government—as many European countries were doing in Africa and throughout the globe—the U.S. aimed to advance its interests through investments and business transactions. American businesses began opening up production sites and markets in Latin America and elsewhere.

William McKinley, elected president in 1896, advanced a much more aggressive foreign policy. McKinley was extremely pro-business, and instead of simply developing commercial markets abroad, McKinley supported military intervention and U.S. acquisition of foreign lands.