Here some intro to the site:
The Monroe Doctrine is a U.S. doctrine which, on December 2, 1823, stated that European powers were no longer to colonize or interfere with the affairs of the newly independent states of the Americas. The United States planned to stay neutral in wars between European powers and their colonies. However, if later on these types of wars were to occur in the Americas, the United States would view such action as hostile. President James Monroe first stated the doctrine during his seventh annual State of the Union Address to Congress, a defining moment in the foreign policy of the United States. Most recently, the Roosevelt Corollary to the Monroe Doctrine (added during the presidency of Theodore Roosevelt) was invoked as a reason to intervene militarily in Latin America to stop the spread of European influence.
