<P> On July 25 , 1898 , during the Spanish -- American War , Puerto Rico was invaded by the United States with a landing at Guánica . As an outcome of the war , the Jones -- Shafroth Act granted all the inhabitants of Puerto Rico U.S. citizenship in 1917 . The U.S. granted Puerto Ricans the right to democratically elect their own governor in 1948 . In 1950 , the Truman Administration allowed for a democratic referendum in Puerto Rico to determine whether Puerto Ricans desired to draft their own local constitution without affecting the unincorporated territory status with the U.S. A local constitution was approved by a Constitutional Convention on February 6 , 1952 , ratified by the U.S. Congress , approved by President Truman on July 3 of that year , and proclaimed by Gov. Muñoz Marín on July 25 , 1952 , the anniversary of the 1898 arrival of U.S. troops . Puerto Rico adopted the name of Estado Libre Asociado ( literally translated as `` Free Associated State '' ) , officially translated into English as Commonwealth , for its body politic . </P>
when did the united states acquired puerto rico
1898