In this installment of Crash Course US History, John Green explores the complex era of American Imperialism during the late 19th and early 20th centuries. The video challenges the notion that American expansion was purely accidental or solely benevolent, arguing instead that it was driven primarily by economic necessities—specifically the need for new markets to sell surplus American goods following the Panic of 1893. Green connects domestic economic crises to foreign policy decisions, illustrating how the search for consumers led the U.S. to acquire territories like Hawaii, the Philippines, and Puerto Rico. The video covers key historical events including the Spanish-American War, the annexation of Hawaii, and the brutal Philippine-American War. It introduces critical figures like Alfred Thayer Mahan, whose theories on naval power influenced strategy, and President William McKinley. The narrative also delves into the social and political debates of the time, highlighting the Anti-Imperialist League and the racial and democratic arguments against empire-building, while contrasting them with the pro-imperialist rhetoric of leaders like Senator Albert Beveridge. For educators, this resource serves as a powerful tool to teach the complexities of foreign policy and the disconnect that can occur between democratic ideals and international actions. It provides opportunities to discuss the role of economics in history, the power of the press (Yellow Journalism), and the constitutional questions surrounding citizenship in acquired territories—questions that remain relevant regarding places like Puerto Rico and Guam today.