On June 19, 1822, the United States formally received the first representative from what was called then "Gran Columbia". Gran Columbia was made up of what became Columbia, Panama, Ecuador and Venezuela. This was the first of the South American nations to declared their independence from Spain and become recognized by the United States. Soon the other newly free South and Central American states, with the exception of Black Haiti, were also recognized by the U. S. (Abraham Lincoln recognized Haiti in 1862.)

During the summer of 1823 there were rumors that Spain might attempt to regain her colonies in South America, in an Alliance with Russia. The United States was concerned about such a possibility, and so were the British. The British foreign minister suggested the United States and Great Britain issue a joint declaration warning the European powers not to intervene. President Monroe consulted with leaders of Congress and the former Presidents, who recommended he proceed with a joint declaration. Secretary of State Adams was opposed the joint statement, believing, if the United States issued the declaration by itself, it would show that the United States was now strong enough to go it alone. It was also important to John Adams, who had presidential aspirations, to show that he, a New Englander and former Federalist, did not have any special affection for the British. Adams' view prevailed and Monroe decided to issue a warning without the British. Monroe issued the declaration of American principals as part of his annual address to Congress. By then, the immediate crisis had passed. However, the doctrine became an important factor in American foreign policy for the next 150 years.

The Monroe doctrine had three components. First, it stated that the areas of North and South America were no longer open to European colonization. Second, it stated that any involvement in the affairs of the Americas by European powers would be considered “dangerous to the peace and safety of the United States. Third, it further stated reciprocally, the United States would not get involved in the affairs of Europe.

The Monroe doctrine marked an important milestone in American Foreign policy. It showed indeed that the United States was a major player on the world stage; a player that could not be ignored. The Monroe Doctrine was used as late as the 1980's to justify American involvement in parts of Central America.

Mahan's Explanation on the meaning of the Monroe Doctrine