What did the Manroe doctrin state?

It warned European powers not to interfere in the affairs of the Western Hemisphere.

Manroe Doctrine was an American policy regarding control of the American continent in 1823. It stated that efforts by European countries to colonize land or intervene with states in North or South America would be seen as the intervention of the US.

This was a message delivered to Congress in December 1823 by James Monroe that the United States would no longer tolerate a colonized or puppet emperor.

The doctrine was conceived to meet the major concerns of the moment, but it soon became a watchdog of American policy in the Western Hemisphere.