From the signing of the armistice in August up until late 1898, Spanish and American diplomats met in Paris to argue over the terms of the peace agreement that would end the Spanish-American War. Most of the terms did not require serious debate. Of course, Cuba would become independent from Spain, with the intention that US occupation forces would eventually leave Cuba to become a free nation, as the Teller Amendment had promised. Also, the US would get Guam, a small Spanish island colony that the US had taken by surprise attack, as well as Puerto Rico. US acquisition of Puerto Rico ended several centuries of Spanish presence in the western hemisphere.
The only major contested issue in the Treaty of Paris was the question of what would happen to the Philippines. Because of Dewey's decisive victory at Manila, President McKinley refused to just give the islands back to Spain, an act he felt would be a cowardly betrayal of the Filipino people. The Spanish, however, had a legitimate complaint. Since it took so long for US ground troops to reinforce Dewey, the actual surrender of Manila, the capital of the Philippines, took place after the American-Spanish armistice was signed. Technically, the US should have stopped all fighting, so the Spanish claimed that the US conquest of the Philippines did not count. The American negotiators offered the Spanish a deal: $20 million dollars for the Philippines. The Spanish accepted this offer.
The question of what to do with the Philippines remained, however. American leaders decided that granting the Philippines self-government would be a prelude to disaster. They came to their decision not only because they had a feeling the Filipinos weren't ready to govern themselves, but because it seemed likely that some other European power would annex the country in short order. In particular, the US was afraid Germany might invade, especially after the German fleet's ominous attempts to intimidate Dewey. Therefore, the US decided to annex the Philippines, in order to "educate and Christianize" the Filipinos. The ultimate goal was to eventually make the Philippines independent, once it was "ready" for self-government. No specific timetable for independence was provided, however.
On December 10, 1898, the US and Spain signed the Treaty of Paris.
The treaty of Paris gave Puerto Rico to the United States, beginning a long relationship between the two countries. Among other things, one of the long- term effects of the Treaty of Paris was that many Puerto Ricans immigrated to the US, especially New York City.
The American annexation of the Philippines in order to "Christianize" the Filipinos seems to make little sense, since the Filipinos were almost entirely Catholic and had been for centuries. Partially, this American desire was based on the American public's ignorance. Many Americans assumed that the Filipinos were all "heathens". Though plenty of Americans knew the Filipinos were Catholics, many Protestants, who considered Catholicism only barely removed from heathenism, still largely dominated political decision making in the US. The decision to annex the Philippines was also justified in terms of an American adoption of the British idea of a "white man's burden", which required that "racially superior" nations such as the United States had a duty to share their wisdom and government with their "little brown and yellow brothers" all over the world. Arguments made for the annexation of Philippines in 1898 represent some of the most racist and paternalistic strains in American thought.
But as is usually the case with the United States, business interests also supported annexation of the Philippines. While Wall Street and business insiders like Mark Hanna had originally opposed the war, they all argued for the annexation of the Philippines. The Philippines, they said, had a population of 7 million people, which was a sizeable new market for American manufactured goods. Also, following Mahan's theories, the Philippines would provide an American coaling station and naval base to protect US trade interests and maintain stability throughout Asian waters. With both the public and big business largely behind annexation, McKinley pushed for the acquisition of the Philippines.
One of the results of the Spanish-American War was that the Mahan's theories of the influence of sea power on history became generally accepted as correct. After the Spanish-American War, in which the US Navy had played such a decisive role and acquired the coaling stations to support a worldwide Navy, the US accelerated growth of the Navy under Elihu Root, secretary of the War Department. (Root also founded the War College.) Therefore, partially because of the Spanish-American War, the US commanded a stronger Navy for World War I (1914-1918) than it might otherwise have had. However, the Philippines, far away from the US, did prove to be an indefensible commitment and a military liability in World War II, when the Japanese quickly overran the island in 1942.