To what extent was the late nineteenth-century and late twentieth-century United States expansionism a continuation of past United...

It can
certainly be argued that the turn to imperialism by the United States in the late nineteenth
century was of a piece with expansionist policy that dated back to the founding of the nation.
Many of the justifications were similar, including a civilizing mission, expanding economic
opportunities, competition with foreign powers, and others. Additionally, the anxieties that
resulted from the closing of the frontier (most famously expressed in Frederick Jackson Turner's
1893 essay The Significance of the Frontier in American ) are often cited as driving forces for
continued expansion as a way of maintaining American vitality in a modern world.

Yet imperialism marked a major departure from previous US policy. For more than a
century, political leaders had emphasized American isolation from the problems of the world. By
mid-century, however, the desire for new markets for United States manufactured goods had
resulted in increasing involvement in foreign affairs. This trend began most conspicuously in
1854, when Commodore Matthew Perry concluded the Convention of Kanagawa, which forcibly opened
Japanese markets to trade.

Over the next fifty years, the United States,
driven by fears of industrial overproduction, moved increasingly toward a policy that emphasized
the acquisition of secure markets, and a military policy that sought naval bases around the
world. This policy, in many ways, was taken to its extreme conclusion with the Spanish-American
War, and the acquisition of the Philippines and Puerto Rico, as well as frequent interventions
on behalf of US investments in Central America before World War I.