The treaty that formally ended the Spanish-American War, signed on December 10, 1898, is known as the Treaty of Paris. This treaty marked a significant shift in the balance of power, as Spain ceded Puerto Rico, Guam, and the Philippines to the United States, effectively ending more than four centuries of Spanish colonial rule in the Americas. The treaty also signaled the emergence of the U.S. as a global power, setting the stage for its involvement in international affairs and colonial expansion. The territorial acquisitions fueled debates over imperialism and liberty, influencing American policy and identity in the 20th century.