In his December 2, 1823, address to Congress, President James Monroe articulated United States’ policy on the new political order developing in the rest of the Americas and the role of Europe in the Western Hemisphere.  

The statement, known as the Monroe Doctrine, was little noted by the Great Powers of Europe, but eventually became a longstanding tenet of U.S. foreign policy. Monroe and his Secretary of State John Quincy Adams drew upon a foundation of American diplomatic ideals such as disentanglement from European affairs and defense of neutral rights as expressed in Washington’s Farewell Address and Madison’s stated rationale for waging the War of 1812. The three main concepts of the doctrine—separate spheres of influence for the Americas and Europe, non-colonization, and non-intervention—were designed to signify a clear break between the New World and the autocratic realm of Europe. Monroe’s administration forewarned the imperial European powers against interfering in the affairs of the newly independent Latin American states or potential United States territories. While Americans generally objected to European colonies in the New World, they also desired to increase United States influence and trading ties throughout the region to their south. European mercantilism posed the greatest obstacle to economic expansion. In particular, Americans feared that Spain and France might reassert colonialism over the Latin American peoples who had just overthrown European rule. Signs that Russia was expanding its presence southward from Alaska toward the Oregon Territory were also disconcerting.
For their part, the British also had a strong interest in ensuring the demise of Spanish colonialism, with all the trade restrictions mercantilism imposed. Earlier in 1823 British Foreign Minister George Canning suggested to Americans that two nations issue a joint declaration to deter any other power from intervening in Central and South America. Secretary of State John Quincy Adams, however, vigorously opposed cooperation with Great Britain, contending that a statement of bilateral nature could limit United States expansion in the future. He also argued that the British were not committed to recognizing the Latin American republics and must have had imperial motivations themselves. …

for the complete article history.state.gov