The Monroe Doctrine was a United States policy of opposing European colonialism in The Americas beginning in 1823. It was enunciated by President James Monroe during his State of the Union address at a time when Spain and Portugal were abandoning their western colonies and intended to preempt other European colonial powers from filling the void. It stated that any effort by by European nations to take control of any independent state in North or South America would be viewed as “the manifestation of an unfriendly disposition toward the United States.” The Monroe Doctrine remained an important U.S. foreign policy throughout the 19th and 20th centuries.