The document provides an overview of America's emergence as an imperial power in the late 19th century. It discusses the Spanish-American War of 1898, which was precipitated by tensions between the US and Spain over Cuba. The sinking of the USS Maine and sensationalized yellow journalism increased American support for intervention. The US defeated Spain and gained control of Puerto Rico, Guam, and the Philippines through the Treaty of Paris, marking the nation's transition from isolationism to imperialism.