To say that the United States acquired the Philippines in a fit of absent-mindedness would be a serious understatement. Conquest of Spain's Pacific possessions (encompassing Guam as well as the Philippine Islands) was not an American war aim in the Spanish-American War, but the unforeseen result of Commodore (later Admiral) George Dewey's crushing defeat, on May 1, 1898, of a squadron of the Spanish fleet in Manila Bay. When informed by Dewey that the city of Manila could be taken at any time, but that some 5,000 additional American troops would be needed to retain it and “control the islands,” President McKinley approved the dispatch of this expedition, but without making clear exactly what the army's mission was to be or what eventual political outcome was desired. Spanish garrison troops in the Philippines at this time amounted to some 10,000 men, but the situation was complicated by the presence of approximately 30,000 Philippine revolutionaries, including a large force then besieging Manila itself. McKinley seems to have assumed initially that the revolutionaries would cooperate with the Americans, but this was quite uncertain, and he soon decided in any case to increase the size of the expedition to 15,000 men. The president's letter of instruction to Major General Wesley Merritt, the expedition's commander, described its mission only as “completing the reduction of the Spanish power” in the islands and maintaining order there while they remained in American hands; nothing was said about whether this occupation was to be temporary or permanent, whether it was to be limited to Manila or extend through some or all of the other islands, or what policy should be followed with respect to the Philippine revolutionary movement. General Merritt foresaw conflict with the rebels and took an expansive view of his instructions, while Major General Nelson Miles, commanding general of the army, thought the president had in mind only a temporary occupation of Manila. This inauspicious beginning was to mark the most overtly imperial chapter in the story of America's overseas engagements. Also, however, it establishes what would prove to be a recurring pattern in our history: inattention to American imperial tasks at the center, and a correspondingly greater freedom of action on the part of America's proconsuls on the periphery.