As the 1820s approached, the young nation was about to announce its first major position on foreign policy. The stability of the Western Hemisphere was being threatened by European events, most notably Spain's intention to reclaim as colonies the Latin American states that had recently gained their independence. In 1823, in his seventh annual message to Congress, President Monroe set forth his opinion that no European nation should attempt to further colonize in the Western Hemisphere, and that they shouldn't interfere with the newly independent Spanish-American republics. He added that the United States would not interfere with existing European colonies or in the European continent itself. Monroe also implied that the United States should complete any further settlement in North America.

While the president's views were not labeled as he spoke them, the remarks became known as the Monroe Doctrine after the mid-1840s. At the time, the United States did not possess the naval power to enforce these sentiments, but the Monroe Doctrine would be used in future generations to justify American occupation of Haiti, the Dominican Republic, and Nicaragua in order to protect them from foreign influence. The Monroe Doctrine remains part of the foreign policy of the United States today.