His order from the President was to destroy the Spanish fleet.

It was given on the first day of the legal existence of the war, counting the day gained, in crossing the Pacific Ocean from the United States to the Philippines, when the 180th degree of longitude west from Greenwich is reached and reckoned.

It was thus the President held back when the war was on; and the next day after Dewey got the order at Hongkong he was on the way.

The Spaniards at Manila could not have been more astonished at Dewey's way of doing, if they had all been struck by lightning under a clear sky.

They had no occasion to be "surprised," having the cable in daily communication with Madrid, and, more than that, a Manila paper of the last day of April contained an item of real news--the biggest news item ever published in that town! It was from a point on the western coast of the island of Luzon, and the substance of it that four vessels that seemed to be men-of-war, had been sighted going south, and supposed to be the American fleet.
What did the Spaniards suppose the American fleet they knew well had left Hongkong was going south for?
If Admiral Dewey had been a commonplace man he would have paused and held a council of war nigh the huge rock Corregidor at the mouth of Manila Bay.