Foundational Principles of U.S. Foreign Policy (Pre-Civil War to Post-Civil War)
📌 Two core beliefs driving early American foreign policy were the Monroe Doctrine, opposing European imperial ambitions in the Western Hemisphere, and Manifest Destiny, the belief in the U.S. mission to expand westward and bring "civilization."
🗺️ Following the Civil War, these foundations supported continued westward expansion into new territories as industrialization began.
🏛️ The Monroe Doctrine established the principle that newly independent South American republics should be free from European powers.

Drivers for Shift in Post-Civil War Foreign Policy
🏭 The industrialization and economic growth in the latter half of the 19th century transformed the U.S. into a major economic and financial power, leading Americans to believe they deserved a share of global commercial benefits.
🚢 Economic growth enabled the U.S. to compete militarily, especially by expanding its Navy, shifting the perception of oceans from barriers to crucial commercial routes, particularly to Asia and the Caribbean.
🏭 Surplus production due to industrialization created a necessity for commercial expansion into foreign markets because domestic markets were insufficient.

The Closing of the Frontier and Ideological Justifications
🧭 The closing of the Western frontier by the late 19th century forced American intellectuals and policymakers to seek new frontiers—financially, economically, or through territorial occupation—to alleviate internal conflicts (e.g., class struggles, immigration pressures).
🧬 The rise of Social Darwinism justified internal exploitation (capitalists vs. workers) and was projected internationally, promoting the belief that Anglo-Saxon white men were biologically entitled to civilize or control other societies ("the white man's burden").
🌐 European and Japanese competition for commercial advantages in vulnerable markets like China alerted U.S. commercial interests that continued isolationism could result in losing crucial financial opportunities globally.

Key Points & Insights
➡️ The U.S. transitioned from a nation viewing oceans as protection to seeing them as commercial gates to global markets due to rapid economic growth.
➡️ The closure of the Western frontier created a need for new external frontiers (territorial/commercial expansion) to manage internal social and economic pressures.
➡️ Social Darwinism provided an ideological justification for overseas expansion by asserting the superiority and duty of white, Anglo-Saxon societies to impose civilization abroad.
➡️ U.S. commercial interests began pressuring policymakers to reconsider isolationism to protect burgeoning investments in Latin America and to compete with European powers in Asia.

📸 Video summarized with SummaryTube.com on Nov 24, 2025, 22:28 UTC