Final answer:
The important result of US participation in the Spanish American War was the acquisition of the Philippines and other territories. Cuba and the Philippines later became independent countries, while Puerto Rico and Guam remained part of the United States.
Step-by-step explanation:
An important result of US participation in the Spanish American War was the acquisition of the Philippines. Along with several other territories, such as Cuba, Puerto Rico, and Guam, the United States gained control of the Philippines after defeating Spain. While Cuba and the Philippines eventually became independent countries, Puerto Rico and Guam remained part of the United States.