In the 1890s, Filipino rebels fought for independence from Spain. The US, wanting to gain control of the Philippines from the Spanish, engaged in what might have been double-dealing with the Filipino insurgents fighting for freedom. If it was not double-dealing, then a great deal of misunderstanding arose between Filipino leader Aguinaldo and the US. Whatever handshake promises US officials may or may not have made, the US never officially recognized the Filipino declaration of independence or the Philippines as an independent state.
Aguinaldo, all the same, understood that the Americans, who said they would support the rebels in fighting Spanish rule, to have verbally promised to acknowledge and respect the Philippines as an independent state. The US, however, made a deal with the Spanish in which they marched into Manila after a staged battle with Spanish troops, then did not allow the Filipino rebel troops to accompany them on a victorious march to take Manila, and finally, accepted a Spanish surrender only to the US. In December 1898, the US announced the "benevolent" assimilation of the Philippines under US rule.
Clearly, this not want the Filipinos wanted. From their point of view, they had simply traded one set of masters for another. They had fought to be an independent state, not a US colony. This state of affairs caused them to fight American rule on their soil.