After a conflict that lasted less than four months, the Treaty of Paris was signed on December 10th, 1898 and ended the war known as the Spanish-American War.
During the late 19th century, the Spanish Empire controlled Cuba. After the sinking of the American warship Maine in Havana under suspicious circumstances, some pushed for war with Spain. Although reluctant at first, republican president William McKinley eventually agreed to the battle after a call for Spain to surrender control of Cuba was rejected.
Despite losses in the thousands on both sides, the naval power of the United States was important in tilting the war in America's favor, especially with a large bulk of Spain's navy at home protecting the country.
In the Treaty of Paris, Spain gave control to the US of not only Cuba, but also Puerto Rico and Guam. The treaty was signed on December 10th, 1898. It was ratified by the Senate the next year, by a vote of 57 to 27.