Final answer:
The Spaniards led by Ferdinand Magellan arrived at Guam and then the Philippines, where they were welcomed by Rajah Humabon. Magellan's trip marked the first circumnavigation of the globe. Later, during the Spanish-American War, Spain ceded Guam and other territories to the United States after Commodore Dewey's victory.
Step-by-step explanation:
Navigating westward through the Pacific Ocean, the Spaniards with their captain, Ferdinand Magellan, arrived at Guam and subsequently to the Philippines. After departing Spain in 1519 and sailing across the Atlantic and around South America, Magellan's fleet sighted Guam on March 6, 1521. They received a respite in Guam, re-supplying fresh water for the crew, who had been at sea for nearly 3 months.
Following Guam, they made landfall in the Philippines, where Magellan and the Spanish were welcomed at the port of Sugbu by Rajah Humabon. Sadly, Magellan's voyage would end in the Philippines, as he was killed in the Battle of Mactan, but his expedition would continue without him, ultimately completing the first circumnavigation of the globe and proving the immensity of the Pacific Ocean.
In contrast to Magellan's arrival, during the Spanish-American War, the United States marked the end of Spain as a colonial power in the Pacific with the victory of U.S. Commodore George Dewey in Manila Bay, Philippines. After this victory, Guam and Puerto Rico surrendered, and Spain recognized Cuba's independence, while also ceding Guam and Puerto Rico to the United States, and allowing the purchase of the Philippines in December 1898.