THE MONROE DOCTRINE
December 2, 1823

You can read the full text of the Monroe Doctrine here (Provided by The Avalon Project at Yale Law school).

If you wish to take a look at the original, click here.

According to Merriam-Webster, a doctrine is a statement of fundamental government policy especially in international relations.

The Monroe Doctrine referred to principles outlined by U.S. President James Monroe in his speech to Congress on December 2, 1823.

In a nutshell,
the Monroe Doctrine announced the following US foreign policy:

European nations should stay out of American affairs and in turn, America was not going to meddle in European affairs.

Sounds familiar? Exactly. George Washington had always thought that this was a good idea. When France had problems with other European nations back then, see French Revolutionary Wars, George overruled his advisers - most notably Secretary of the Treasury Alexander Hamilton and Secretary of State Thomas Jefferson - and recommended political neutrality.

Mastermind behind the Monroe Doctrine was John Quincy Adams, then Secretary of State.

The Monroe Doctrine was never a ratified law or anything like that. It was just a general guideline according to which the US resolved to handle their foreign affairs.

At the time of this statement, nobody outside of the United States really cared about the announcement. In fact, it took at least 30 years after Monroe's speech until the Monroe Doctrine was called Monroe Doctrine. But future US governmental officials kept referring to the proclamation and other nations realized that the U.S. was serious about the Monroe Doctrine.

Most famous referral to (i.e. pressure by means of) the Monroe Doctrine was performed when France tried to make Mexico a French colony, see French-Mexican War. It worked and in 1867 the French sailed back home.