The primary purpose of the Monroe Doctrine, articulated in 1823 by President James Monroe, was to prevent European powers from further colonizing or interfering in the Americas. It sought to establish the Western Hemisphere as a sphere of U.S. influence, asserting that any European intervention in the affairs of independent nations in the Americas would be seen as a threat to U.S. security. This doctrine fundamentally shaped U.S. foreign policy, asserting American dominance in the Western Hemisphere and laying the groundwork for future interventions and influences in Latin America.