Final answer:
President William McKinley sent the battleship USS Marine to Cuba to support the Cuban rebels and protect American interests.
Step-by-step explanation:
President William McKinley decided to send the battleship USS Marine to Cuba during the Spanish-American War in 1898. The main reason for this decision was to support the Cuban rebels who were fighting for independence from Spain. The USS Marine was sent to provide a show of force and to protect American interests in Cuba.
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