Final answer:
The United States sent the battleship Maine to Havana, Cuba to protect U.S. interests during the Cuban war for independence in 1898. The explosion of the Maine, although later determined to be an accident, led to a declaration of war on Spain.
Step-by-step explanation:
The United States sent the battleship Maine to Havana, Cuba in order to protect U.S. interests and observe the situation during the Cuban war for independence in 1898. The U.S. had significant investments in Cuba, including control of the sugar industry, communications, and transportation infrastructure. The explosion of the Maine, although later determined to be an accident, was blamed on Spain by sensationalist U.S. press, leading to a declaration of war on Spain by the U.S. Congress.