Commodore George Dewey achieved a crushing naval victory over the Spanish fleet in the waters west of the city of Manila in the Philippines on 1 May 1898 during the Spanish-American War (21 April to 13 August 1898). Although the operation had long been a part of the U.S. Navy's strategic plans in the event of a conflict with Spain, no one, even at the start of the war could foresee the impact Dewey's success would have on the future of the United States.
Beginning in 1894 the Naval War College (and later special boards convened by the Secretary of the Navy) examined the possibility of war with Spain over trouble in Cuba. An attack by the U.S. Asiatic Squadron against the Spanish forces in the Philippines first became a part of the Navy's plans in 1896. The objective of the offensive operation was not to conquer all or part of the Spanish colony, but to tie down or divert enemy ships and give the United States' a stronger bargaining position at the peace settlement. Nevertheless, the consequences of Dewey's triumph were much different.
Assistant Secretary Roosevelt telegraphed Commodore George Dewey on 25 February ordering him to concentrate the ships of the Asiatic Station at Hong Kong. In the event of war he was to take his squadron and destroy the Spanish ships in Philippine waters. Dewey's command at Hong Kong consisted of the protected cruisers Olympia, Boston, and Raleigh, and the gunboats Concord and Petrel. The Revenue Cutter McCulloch joined the force on 17 April, and the protected cruiser Baltimore arrived on 22 April. Dewey also prepared for future operations in a region without friendly bases by purchasing the British steamers Nanshan and Zafiro to carry coal and supplies for his squadron.
In a meeting called by the governor general of the Philippines on 15 March, Rear Admiral Patricio Montojo y Pasaron, in command of Spanish naval forces in the colony, expressed his opinion that his squadron would be destroyed by the onslaught of the ships of Dewey's squadron. The Spanish naval force consisted of seven unarmored ships carrying thirty-seven heavy guns and weighing a total of 11,328 tons. Montojo's largest ship was made of wood. Dewey's force that eventually engaged the Spanish squadron was much stronger, consisting of six steel vessels mounting fifty-three guns and displacing 19,098 tons. Four of these had armored decks. Montojo recommended fortifying the entrances to Subic Bay, northwest of Manila, and moving his ships there to await Dewey's attack. If the Americans bypassed Subic and anchored in Manila Bay, it was thought, Montojo could sneak up on them during the night and inflict some damage. The governor general agreed. However, Montojo did not track the progress of the work in Subic Bay.
Secretary Long telegraphed Commodore Dewey at Hong Kong on 21 April informing him that the U.S. blockade of Cuba had begun and that war was expected at any moment. On 24 April, British authorities informed the commodore that war had been declared and he must leave the neutral port within twenty-four hours. Dewey also received a telegram from the Navy Department, instructing him to proceed immediately to the Philippine Islands and begin operations against the Spanish fleet. However, Dewey wanted to receive the latest intelligence from the American consul at Manila, Oscar Williams, who was expected daily. The American squadron moved to Mirs Bay on the Chinese coast thirty miles east of Hong Kong to await a circulating pump for the Raleigh and the arrival of Williams. They spent two days drilling, distributing ammunition, and stripping the ships of all wooden articles (which could add to the damage of fires on board ship caused by enemy gunfire). Almost immediately after Williams arrived on 27 April, the American squadron departed for the Philippines, in search of the ships of the Spanish squadron.
After learning that war had been declared, Admiral Montojo took his squadron into Subic Bay only to discover that the commander there still needed another six weeks to mount his guns on Isla Grande at the bay's entrance. On 28 April the Spanish admiral learned that the Americans had left Mirs Bay bound for the Philippines. After calling a council of his captains, he returned with his ships to Manila Bay. The two passages into the latter were guarded by seventeen guns including nine obsolete muzzle loaders. The Spanish attempted to mine the main channel, but the water was so deep and the entrance so wide that neither mines nor shore batteries were an effective barrier to enemy ships passing through during the night. Of the more than 200 guns near the city of Manila, only twelve were breech-loaders positioned to fire out to sea. Montojo rejected the idea of fighting under the guns of the city because civilian structures would likely be hit by American fire. The Spanish decided to anchor their ships in the shallow waters under the guns of the Cavite arsenal, on a small peninsula seven miles southwest of Manila. Deeply pessimistic about his fleet's chances of survival, Montojo believed it best to give his men a better chance to escape from their vessels should they be sunk in the upcoming battle.
Consul Williams accurately reported that Montojo intended to fight his squadron while under the guns in Subic Bay, and Dewey sent two of his cruisers to reconnoiter. Finding Subic Bay empty, and in defiance of the reports of mines in the channel, the Americans pressed on into Manila Bay and discovered the Spanish squadron near Cavite. Leaving his two auxiliaries in the bay guarded by the McCulloch, Dewey formed his remaining ships into a line and steamed in a oval pattern along the five-fathom curve, pouring a heavy fire into the outgunned and obsolete Spanish force. The enemy replied with wildly inaccurate gunfire from their ships and two 5.9 inch guns on Sangley Point. The Americans scored critical hits on the larger Spanish warships, setting them ablaze. After nearly two hours of fire, Dewey ordered his captains to withdraw, acting on reports that his ships were running low on ammunition.
Dewey took his squadron five miles off Sangley Point and signaled his captains to come on board and report their condition. The commodore discovered that his squadron had sustained very little damage and that he had plenty of ammunition to continue the battle. After allowing the crewmen to enjoy a light meal, Dewey ordered his ships to reengage the remnants of Montojo's shattered squadron. The Spanish admiral had pulled his surviving vessels behind Cavite into the shallow waters of Bacoor Bay to make a final stand. Hitting the Spanish ships in their new anchorage proved difficult, and Dewey ordered the gunboats Concord and Petrel, with their shallow draft, to finish off the enemy at close range. The garrison at Cavite raised a white flag at about 12:15, and the firing ended shortly thereafter.
Montojo's fleet was destroyed, suffering 371 casualties compared to only 9 Americans wounded. When official word on the magnitude of the U.S. Navy's victory reached the United States, nearly a week later, the American public heaped enthusiastic praises on Dewey as wild celebrations eruption throughout the country. However, 26,000 Spanish regulars and 14,000 militia garrisoned various points in the Philippine Islands including 9000 at Manila. The U.S. squadron took control of the arsenal and navy yard at Cavite and Dewey cabled Washington stating that, although he controlled Manila Bay, he needed 5000 men to seize Manila itself.
The completeness of Dewey's victory, so early in the war, prompted the administration of President William McKinley to send the troops necessary to capture Manila from the Spanish. The U.S. Army sent substantially more than Dewey asked for, with 10,844, under the command of Major General Wesley Merritt, reaching the Philippines before the end of the war.
Meanwhile, Dewey had brought the Filipino insurgent Emilio Aguinaldo to Cavite in May hoping to learn more about the Spanish garrison and welcoming any distraction the Filipino rebels might provide by their operations against Spanish forces. However, Dewey and the American consuls in the Far East overestimated their ability to control the consequences of these actions, which included Aguinaldo's expectation that the United States would support his demand for the colony's independence. By the time American forces were prepared to assault Manila in August, the potential problems of cooperating with the rebels became apparent to Dewey and Merritt. The American commanders reached an oral agreement with the governor- general at Manila to surrender the city after a brief naval bombardment and infantry assault. On the morning of 13 August the guns from the U.S. squadron opened fire and Merritt's troops went forward. After sharp fighting in some quarters the Spanish surrendered, allowing the Americans to occupy Manila, keeping the Filipino insurgents out of most sections of the city. The peace protocol was signed between the United States and Spain on 12 August, but word of this did not reach Manila until four days later.
The negotiations that led to the United States accepting control of the Philippine Islands are too lengthy to relate here in detail. Pressured by expansionists, and fearing that another European nation would fill the vacuum created by the collapse of Spanish colonial power, President McKinley decided that the United States should take over administration of the islands. It was left to a future American government to turn control of the country to the Filipinos. For the most part, the United States reluctantly became a colonial power in the Pacific. Dewey's victory at Manila Bay began a series of events that dramatically increased America's interests and commitments across the great ocean.