Chapter 27: Empire & Expansion – The Spanish-American War

The late nineteenth and early twentieth centuries witnessed the pivotal transformation of the United States from an internally focused, isolationist nation to a burgeoning global empire, a shift driven by economic necessity, heightened nationalism, and competition with established European colonial powers. Key catalysts included the search for new overseas markets for booming industrial and agricultural production, the sensationalist influence of the “yellow press”, and intellectual movements promoting American cultural superiority and naval strength, notably Josiah Strong’s advocacy for Anglo-Saxon civilization and Alfred Thayer Mahan’s doctrine on sea power. This era of expansion culminated in the Spanish-American War of 1898, ignited by the Cuban revolt against Spanish oppression, fueled by yellow journalism coverage of atrocities like those committed under “Butcher” Weyler, and propelled by the mysterious explosion of the battleship Maine. The swift American victory resulted in the acquisition of strategic territories including Guam and Puerto Rico, the formal annexation of Hawaii, and the decision to acquire the Philippines for $20 million, leading to the suppression of a nationalist rebellion led by Emilio Aguinaldo. This territorial expansion sparked a vigorous domestic debate between imperialists, who invoked economic destiny and the "White Man's Burden," and anti-imperialists, who formed organizations like the Anti-Imperialist League to argue that overseas despotism violated American principles of self-determination. The Supreme Court addressed the legal status of the new possessions in the Insular Cases, determining that the Constitution did not necessarily extend all rights to these new territories. Meanwhile, the U.S. exerted commercial influence in Asia through Secretary of State John Hay’s Open Door notes, seeking to ensure equal trade access in China and respect for its territorial integrity, particularly following the Boxer Rebellion. After President McKinley's assassination in 1901, Theodore Roosevelt assumed the presidency, advocating the "big stick" approach to foreign policy. Roosevelt prioritized the construction of the Panama Canal for military and commercial mobility, facilitating the Panamanian revolution against Colombia to secure the Canal Zone in 1903. He further cemented U.S. dominance in the Western Hemisphere through the Roosevelt Corollary to the Monroe Doctrine, establishing the U.S. as the regional police force to manage Latin American debt and prevent European intervention. Roosevelt later acted as a global mediator, settling the Russo-Japanese War in 1905 and easing diplomatic tensions with Japan over discriminatory policies in California through the Gentlemen’s Agreement and the display of American naval power via the Great White Fleet tour.