On December 2, 1823, President James Monroe articulated what became known as the Monroe Doctrine in his annual message to Congress. He declared that the Western Hemisphere was no longer open to European colonization and warned against European interference in the affairs of newly independent Latin American nations. In return, the United States pledged not to involve itself in internal European conflicts. The policy had limited immediate enforcement power but carried strong symbolic weight. Over time, later presidents and policymakers invoked the Monroe Doctrine to justify U.S. influence in the Americas, sometimes in ways far beyond Monroe’s original language. It remains one of the most cited statements in U.S. diplomatic history.
