A war between Spain and the United States, fought in 1898. The war began as an intervention by the United States on behalf of Cuba . Accounts of Spanish mistreatment of Cuban natives had aroused much resentment in the United States, a resentment encouraged by the yellow press ( see yellow journalism ). The incident that led most directly to the war was the explosion of the United States battleship Maine in the harbor of Havana , Cuba, an incident for which many Americans blamed Spain ( see Remember the Maine ). The United States won the war easily. The best-remembered incidents in the Spanish-American War were the charge of the Rough Riders , led by Theodore Roosevelt , in the Battle of San Juan Hill in Cuba, and the Battle of Manila Bay in the Philippines , at which Admiral George Dewey said, “You may fire when you are ready, Gridley.” The United States acquired Puerto Rico , Guam , and the Philippines in the war and gained temporary control over Cuba.