The term 'President with a Doctrine' refers to James Monroe, the fifth President of the United States. He is best known for his foreign policy doctrine, which was issued in 1823 and declared that any attempt by European powers to colonize or interfere with the affairs of the Americas would be seen as an act of aggression. This doctrine helped to protect the newly independent nations of Latin America from European interference and established the United States as a major power in the region.