U.S. history please help, best answer gets 10 points !!?

According to Wikipedia the Monroe Doctrine was a United States policy introduced on December 2nd 1823 that said that further efforts by European Governments to colonize land or to interfere with states in the Americas would be viewed by the United States of America as acts of aggression requiring US intervention. The Monroe Doctrine erted that the Western Hemisphere was not to be further colonised by European Countries and that the United States would not interfere with existing European colonies nor in the internal concerns of European Countries.