During the tenure of James Monroe, the 5th us president, the country acquired Florida and Maine and warned Europe to forget about interfering in the Americas. President James Monroe said no European power should, in the future, try to establish a colony anywhere in the Americas, further noting that the political system of the European powers was somewhat different from that of the Americas.
Monroe declared any effort to extend this European system to any of the Americas would endanger the peace and safety of the United States.
