In what year did the U.S. officially annex the Philippines?

The United States officially annexed the Philippines in 1898, following the conclusion of the Spanish-American War. This war began in April 1898, primarily as a result of tensions stemming from U.S. support for Cuban independence from Spain. As part of the war, the United States engaged in military action in the Philippines, which was then a Spanish colony.

After the victory in the war, the Treaty of Paris was signed in December 1898, which resulted in Spain ceding the Philippines, Guam, and Puerto Rico to the United States in exchange for $20 million. This marked a significant moment in U.S. history, as it represented the country's expansion overseas and its emergence as a global imperial power.

The other years listed are significant in their own right, but they do not correspond to the official annexation of the Philippines. For example, 1896 is notable for events leading up to the Spanish-American War, while 1900 and 1902 represent later stages of American governance in the Philippines, including issues of colonial administration and the Philippine-American War, which arose in response to the U.S. annexation. However, the formal act of annexation occurred in 1898, making it the correct answer.