On Feb. 15, 1898, the USS Maine, a battleship, exploded in the Cuba’s Havana harbor, killing 260 American sailors. An official U.S. Naval Court of Inquiry ruled in March 1898 that the ship was blown up by a mine, without directly blaming Spain. Nonetheless, Congress declared war and, within three months, the U.S. had decisively defeated Spanish forces. On December 12, 1898, the Treaty of Paris was signed between the U.S. and Spain, granting the United States its first overseas empire with the ceding of such former Spanish possessions as Puerto Rico, Guam, and the Philippines. In 1976, a team of American naval investigators concluded that the Maine explosion was likely caused by a fire that ignited its ammunition stocks, not by a Spanish mine or act of sabotage.