In January 1898, fearing the fate of American interests in Cuba due to the war, the cruiser USS Maine was dispatched to protect them.

Less than a month later, the cruiser exploded while lying at anchor in Havana harbor, killing 261 sailors onboard and inflaming American opinion.

The U.S. Asiatic Squadron commanded by Dewey, a veteran of the American Civil War, was dispatched to ensure success.

Upon realising that the battle was hopeless, Montojo ordered his two protected cruisers to be scuttled to ensure that they did not fall into the hands of the Americans.

[7] Americans living on the West Coast of the United States feared a Spanish attack at the outbreak of the Spanish–American War.

Admiral Montojo, a career Spanish naval officer who had been dispatched rapidly to the Philippines, was equipped with a variety of obsolete vessels.

[8]: 59  Administrative actions worked against the effort, sending explosives meant for naval mines to civilian construction companies while the Spanish fleet in Manila was seriously undermanned by inexperienced sailors who had not received any training for over a year.

[8]: 69  Montojo compounded his difficulties by placing his ships outside the range of Spanish coastal artillery (which might have evened the odds) and choosing a relatively shallow anchorage.

[14] Passing the entrance, two Spanish mines exploded but were ineffective as they were well below the draft of any of the ships due to the depth of the water.

[9] At 5:41 with the now famous phrase, "You may fire when ready, Gridley",[1] the Olympia's captain was instructed to begin the destruction of the Spanish flotilla.

[15] The U.S. squadron swung in front of the Spanish ships and forts in line ahead, firing their port guns.

Eight Spanish ships, the land batteries, and the forts returned fire for two and a half hours although the range was too great for the guns on shore.

Reports arrived during the conference that sounds of exploding ammunition had been heard and fires sighted on the Cristina and Castilla.

At 10:40 a.m. action was resumed but the Spanish offered little resistance, and Montojo issued orders for the remaining ships to be scuttled and the breechblocks of their guns taken ashore.

The Olympia, Baltimore and Boston then fired on the Sangley Point battery putting it out of action and followed up by sinking the Ulloa.

According to American sources, Dewey won the battle[15] with seven men very slightly wounded,[16] a total of nine injured, and only a single fatality among his crew: Francis B. Randall, Chief Engineer on the McCulloch, from a heart attack.

[6] According to Rodríguez, Dewey may have concealed the deaths and injuries by including the numbers among the 155 men who reportedly deserted during the campaign.

The completeness of the victory in the opening stages of the war prompted President McKinley to send additional troops to seize the city.

Building on his popularity, Dewey briefly ran for president in 1900, but withdrew and endorsed William McKinley, the incumbent, who won.

Union Square, San Francisco features a 97 ft (30 m) tall monument to Admiral George Dewey's victory at the Battle of Manila Bay.

[2] Engaged Vessels: Despite the superiority of the American artillery, the success rate of their guns was minimal, a total of 5,859 shells were expended during the battle.