<P> On 25 April 1898, Commodore George Dewey, Commander of the United States Asiatic Fleet, received word that war with Spain had been declared and was ordered to leave Hong Kong and attack the Spanish fleet in Manila Bay . </P> <P> In the Philippines, Rear Admiral Patricio Montojo, realizing that Subic Bay would provide a more defensible position than Cavite, ordered his smaller ships and the batteries in Manila Bay to resist Dewey's fleet and deny them the entrance to Manila Bay . His other units would then use Subic Bay as a sally port, with which he could attack the American fleet's rear and cut off its supplies . On 26 April, Montojo arrived at Subic Bay aboard Reina Cristina with seven other ships . </P> <P> On the morning of the 27 April, Castilla was towed northeast of Grande Island to help control the western entrance to Subic Bay . The eastern entrance, which was between Grande and Chiquita Islands, had been blocked by the scuttling of San Quintín and two other vessels . On Grande Island, the four 5.9 - inch (150 mm) Ordóñez guns that had been shipped from Sangley Point were not yet installed . Meanwhile, a cable - laying ship, which was commandeered to lay mines, ended up putting only four of the 15 available mines in place . </P> <P> In Hong Kong, Dewey purposely delayed his sailing until he received news from the U.S. Consul at Manila, Oscar F. Williams, about information about the strength and positions of the Spanish fleet . Williams told Dewey that Montojo and his fleet had sailed to Subic Bay . </P>

What caused the closure of a u.s. military base at subic bay