The Monroe Doctrine

The American continents... are henceforth not to be considered as subjects for future colonization by any European powers." With these words, President James Monroe announced his foreign policy to the world. It became known as the Monroe Doctrine.

- Carolyn Gard and Andrew Matthews

Over the decades, other U.S. presidents have used variations of it to warn foreign nations against interfering in the politics of the Western Hemisphere. Some presidents have used it to insert the United States in the affairs of its neighbors.

For Monroe, threats from Europe inspired him to take this step. In 1821, several Spanish colonies in the Americas had declared their independence. The United States recognized those places as new countries. In Europe, however, the Holy Alliance urged Spain to reclaim its empire in the New World.

The United States was determined to prevent European nations from threatening the new republics in its "sphere of influence." Monroe introduced the Monroe Doctrine in his seventh annual address to Congress on December 2, 1823. He told Congress "We should consider any attempt on [the part of the European nations] to extend their system to any portion of this hemisphere as dangerous to our peace and safety."

The doctrine stated that the United States would not interfere in the affairs of Europe or its colonies. It also insisted that North and South America were not subjects for future colonization by European powers. The doctrine made clear that interference by a European power in a Western country that had declared its independence would be considered a threat to the United States.

It was a bold statement. In the 1820s, the young United States did not have the military or political might to back up its new policy. Yet the Monroe Doctrine governed the foreign policy of the United States for many years.