<P> On July 25 , 1898 , during the Spanish -- American War , the U.S. invaded Puerto Rico with a landing at Guánica . As an outcome of the war , Spain ceded Puerto Rico , along with the Philippines and Guam , then under Spanish sovereignty , to the U.S. under the Treaty of Paris , which went into effect on April 11 , 1899 . Spain relinquished sovereignty over Cuba , but did not cede it to the U.S. </P>
who did puerto rico belong to before the u.s
Spain