Protestantism began to develop in the Philippines after the Spanish–American War when the United States acquired the Philippines from the Spanish with the 1898 Treaty of Paris. During American Colonial Period, the Catholic Church was disestablished as the state religion, giving Protestant missionaries more opportunities to enter the islands. In addition, there was a backlash against the Hispanic Catholicism and a greater acceptance of Protestantism represented by the Americans. The dominance of the Catholic Church in all aspects of life in Spanish Philippines and Protestant anti-Catholic animosity were prominent reasons for the start of Protestant missionary activity. In 1901 the Evangelical Union was established in the Philippines to co-ordinate activities amongst the Protestant denominations and lay the foundations for an indigenous religious movement.