Interest in Cuba- The United States and the Caribbean region were linked economically. The U.S. companies invested heavily in the sugar, coffee, and banana plantations. Another reason is because they are 90 miles away from the coast of Florida. Also because their struggle for independence attracted U.S. sympathy.
Interest in Guam, Puerto Rico, and the Filipinos- The U.S. only had an interest in Cuba. The only reason they got these Spanish countries is because of the Treaty of Paris. Which ended the war and Spain handed Over These countries.