The Carribean drew U.S. attention for many reasons. The United States had long-held interest in the Caribbean for many reasons:
The U.S. wanted to rid the Western Hemisphere of European colonial powers
Many U.S. leaders believed that they need to take control of the Caribbean to protect its shores and shipping routes
The U.S. had invested heavily in the sugar, coffee, and banana plantations and they had plans to build a canal across the isthmus of Panama
Americans were sympathetic to the brutal Spanish tactics and the struggle for the Cuban's independence
In February 15, 1898, the U.S.S. Battleship Maine was sunk in Havana Harbor under mysterious circumstances. This event sealed the decision for military intervention.
On April 20, 1898, U.S. Congress passed a joint resolution that acknowledged Cuban independence, demand Spain to give up control of Cuba, and allowed President William McKinley to use all military measures he deemed fit to guarantee Cuba's independence. Spain rejected this resolution and the U.S. government voted to go to war with Spain on April 25.
U.S. and Spanish governments signed the Treaty of Paris on December 10, 1898. Apart from guaranteeing the independence of Cuba, the treaty also forced Spain to cede Guam and Puerto Rico to the United States. Spain also agreed to sell the Philippines to the United States for the sum of $20 million.