The Philippine Islands is claimed as an American Possession in December of 1898
The U.S. claim to possession of the Philippine Islands was an unplanned outcome of the Spanish-American War of 1898. This very short war (3 1/2 months with only four days of actual combat) was begun with the sole objective the expulsion of Spain from Cuba and was settled by a peace treaty in late December of 1898. But, in a surprise move, President William McKinley insisted that Spain "cede" their last remaining colony to the United States. (For a more thorough account see "McKinley's Ghost" on this website). This in turn led directly to a very long and nasty war with Philippine revolutionaries led by Emilio Aguinaldo, who had no intention of trading one colonial overlord for another. The war, known today as the Philippine-American War (a.k.a. "Philippine Insurrection"), began on February 4, 1899 and was proclaimed as ended by President Theodore Roosevelt on July 1, 1902, although pockets of resistance to American rule lasted for several more years.
At the onset of the war, Brigadier General John C. Bates negotiated written and oral agreements with a majority of the Moro peoples to remain neutral during the conflict with their Christian cousins in the north. But longer-term Moroland and the Moros would become an enigma to the Americans. Where, if at all, did the Muslims and their unique culture fit into President McKinley's grand dream of of eventually creating a new nation, in a clearly American image? It was a question which would later be called "the Moro Problem", vex four Presidents and their administrations, and become a long, never fully resolved struggle that exists to this day albeit in a somewhat different form.