During the mid-1800's Monroe's declaration which combined with the ideals of Manifest Destiny, provided guidance and support for the United States' expansion on the American continent. In the late 1800's the United States' economic and military power enabled it to enforce the Monroe Doctrine. But it was Theodore Roosevelt's Corollary that greatly extended it. The Doctrine, issued by President James Monroe in 1823, had basically warned European powers not to interfere in the Western Hemisphere's affairs. Its three main concepts included non-colonization, non-intervention, and separate sphe…
