Although the U.S. was not planning to interfere in the conflict between Cuba and Spain, several factors urged the government to change its mind. On February 15, 1898, the USS Maine, which was sent by the American government to Havana, exploded. The American press reacted to this event very aggressively, blaming Spain for this tragedy and persuading Americans that the US had no other choice other than military intervention. Also, the rising popularity of imperialism urged the nation to think that the war with Spain was the perfect way to show that America had the strength to challenge other powerful states and influence global affairs.The first step of the U.S. was to eliminate Spanish battleships in the Philippines to ensure the superiority of the North Atlantic Squadron and weaken Spain. The Commodore of the Asiatic Squadron George Dewey entered the Manilla Bay with his nine ships and destroyed the old Spanish fleet, sinking eight vessels. Apart from several wounded sailors, Americans had no casualties, and the whole operation was very successful.
At that time, the forces of Admiral Cervera came from European waters to the harbor at Santiago de Cuba. The U.S. military forces led by General Shafter landed near Santiago and started advancing toward the city, urging Cervera and his people to leave it. On July 3, the Spanish Admiral led his ships away from Cuba and suffered heavy losses from the attack of the U.S. fleet. Eventually, the destruction of his squadron led to the capitulation of Spanish forces.
Under the Treaty of Paris, Spain ceded Puerto Rico and Guam to the United States. America also demanded authority over the Philippines. Spain reluctantly agreed to this and asked for $20,000,000 in return. Thus, the U.S. became an empire and gained an important base for interventions in the Pacific region. Spain, in its turn, lost all its foreign territories and started focusing on domestic affairs.