Why did the United States become involved in the Philippines' affairs?

The United States became involved in the Philippine's affairs and eventually took over control of the Philippine's during the Spanish American War. The Philippines were previously a Spanish colony and when the U. S. defeated the Spanish in war they took control of the territory.

The Philippine-American War, 1899-1902. After its defeat in the Spanish-American War of 1898, Spain ceded its longstanding colony of the Philippines to the United States in the Treaty of Paris.