During his annual address to Congress, President James Monroe proclaims a new U.S. foreign policy initiative that becomes known as the "Monroe Doctrine." Primarily the work of Secretary of State John Quincy Adams, the Monroe Doctrine forbade European interference in the American hemisphere but also asserted U.S. neutrality in regard to future European conflicts.
The origins of the Monroe Doctrine stem from attempts by several European powers to reassert their influence in the Americas in the early 1820s. In North America, Russia had attempted to expand its influence in the Alaska territory, and in Central and South America the U.S. government feared a Spanish colonial resurgence. Britain too was actively seeking a major role in the political and economic future of the Americas, and Adams feared a subservient role for the United States in an Anglo-American alliance.
The United States invoked the Monroe Doctrine to defend its increasingly imperialistic role in the Americas in the mid-19th century, but it was not until the Spanish-American War in 1898 that the United States declared war against a European power over its interference in the American hemisphere. The isolationist position of the Monroe Doctrine was also a cornerstone of U.S. foreign policy in the 19th century, and it took the two world wars of the 20th century to draw a hesitant America into its new role as a major global power.