With colonial power in 1898, the United States' role in the world changed to that of isolation and expansion. There are three main US ideologies that contributed to the change of the role of America in the world, Manifest Destiny, the Monroe Doctrine and the Open Door Policy. From the time of President Washington, Americans have believed in the theory of manifest destiny. "Manifest Destiny was the idea that it was the obvious destiny of the United States to expand on the continent of North America." (http://historicaltextarchive.com/sections.php? op=viewarticle&artid=297).
In December of 1823 President James Monroe launched a doctrine, which would bare his name, to the US Congress. Monroe went against European involvement in the dealings of the Americas. "It would have been of benefit to all had the US not, under the guise of fighting against external colonialism, focused its foreign policy on constituting a continental block that the US itself hoped to dominate."
(http://mondediplo.com/2003/ 05/03lemoine) The Monroe Doctrine defied the intervention of any European colonial power in the Americas with the US already the colonial power there. "Although Americans granted that they owed much too classical and British heritage, they, believed that New World and American genius had made the US distinctly better." (http://historicaltextarchive.com/ sections.php?op=viewarticle&artid=297).
Lastly the Open Door Policy kept US relations with Asia in order to protect US Spheres of Influence. "On September 6, 1899, Secretary of State John Hay issued the Open Door Note Policy. " Hay asked the powers of Germany, Italy, Russia, France, Japan, and Great Britain to respect the principles of equal trade in their spheres of influence: the same tariffs, harbor dues and railway fares were to apply to all nations and the spheres were to be open for citizens of all nations." (http://www.fortunecity.com/ victorian/picasso/50/amcenBII4.htm) The policy emphasized American...