When Spain lost to America, Spain surrendered the Philippines and other territories to the Americans and conquered the country. The Americans raised their flag and claimed their territory at Fort Santiago at August 13 1898. Fort Santiago became the headquarters of the Philippine Division of the United States Army.

The Americans made drastic changes immediately.
The Ayuntamiento became the seat of the Philippine Commission of the United States in 1901.
The breach of city walls of the southwestern end of Calle Aduana, the eastern end of Calle Anda, the northeastern end of Calle Victoria and the southeastern end of Calle Palacio.
The transformation of moats that surrounded Intramuros into a municipal golf course by the city.

Emilio Aguinaldo led a rebellion against the Americans on November 19 1899. The other Filipino generals like General Licerio Geronimo attacked U.S. Troops on San Mateo in on December 19 1899 that resulted in killing a U.S Military General. Other battles have been fought in different places like Catubig, Cagayan De Misamis, Matibac, and more. After the battles, The U.S. Congress approved the Philippines Act on July 1, 1902, and the Philippines was given limited self-government.