Riots in Havana by pro-Spanish "Voluntarios" gave the United States reason to send in the warship . This action by the U.S. indicated high national interest. Tension among the American people was raised because of the explosion of the USS "Maine", and "yellow journalism" that accused Spain of extensive atrocities, agitating American public opinion. The war ended after decisive naval victories for the United States in the Philippines and Cuba. The Treaty of Paris ended the conflict 109 days after the outbreak of war giving the United States ownership of the former Spanish colonies of Puerto Rico, the Philippines and Guam.