After the Adams-Onis treaty which gave Florida to the USA, and solved a dispute with eh borders of the Lousiana Purchase. James Monroe was concerned that Spain and other European countries would reconquer their old colonies (most of which revolted and became independent). So James Monroe wrote the Monroe Doctrine which formulated a declaration of principles on South America. He warned that, quote, "the American Continents, by the free and independent condition which they have assumed and maintain, are henceforth not to be considered as subjects for future colonization by any European power."
