Title: Military history of Puerto Rico
Content:  Puerto Rico, in the short-lived revolution known as the Grito de Lares and culminating with the Intentona de Yauco. The island was invaded by the United States during the Spanish–American War. After the war ended, Spain officially ceded the island to the United States under the terms established in the Treaty of Paris of 1898. Puerto Rico became a United States territory and the "Porto Rico Regiment" (Puerto Rico's name was changed to Porto Rico) was established on the island. Upon the outbreak of World War I, the U.S. Congress approved the Jones–Shafroth Act, which extended United States citizenship (the Puerto Rican House of Delegates rejected US citizenship) with limitations upon Puerto Ricans and made them eligible for the military draft. Since then, as citizens of 
Title: Political status of Puerto Rico
Content:  The United States acquired the islands of Puerto Rico in 1898 after the Spanish–American War, and the archipelago has been under U.S. sovereignty since. In 1950, Congress enacted legislation (P.L. 81-600) authorizing Puerto Rico to hold a constitutional convention and in 1952, the people of Puerto Rico ratified a constitution establishing a republican form of government for the island. After being approved by Congress and the President in July 1952 and thus given force under federal law (P.L. 82-447), the new constitution went into effect on July 25, 1952. Puerto Ricans have been U.S. citizens since 1917. After the promulgation of the Commonwealth constitution in 1952, the government of the Commonwealth 
Title: Río Prieto, Lares, Puerto Rico
Content:  The United States acquired Puerto Rico from Spain in the aftermath of the Spanish–American War under the terms of the Treaty of Paris of 1898. In 1899, the United States conducted its first census of Puerto Rico finding that the population of Río Prieto barrio was 1,931.
Title: Statehood movement in Puerto Rico
Content:  Following the Spanish–American War, Puerto Rico was ceded to the United States in 1898, through the signing of the Treaty of Paris. Puerto Rico became an unincorporated, organized territory of the US through a series of judicial decisions by the Supreme Court of the United States, collectively known as "The Insular Cases" and the enactment of several statutes by Congress. In 1900, the U.S. Congress enacted the Foraker Act, establishing a civil government in the territory and then in 1917, Puerto Ricans were granted US citizenship, by the enactment of the Jones-Shafroth Act. The Office of the President is responsible for policy relations between the United States and Puerto Rico, although according to the Territorial Clause of Constitution of the United States of America "The Congress shall have power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States...". In 1952, voters in Puerto Rico approved a new constitution proposed by Gov. Luis Munoz Marin; this led to the territory being designated as a commonwealth.
Title: José Maldonado Román
Content:  the chase, the insurgents asked Emerson when will the Americans come to help liberate them from the Spaniards, to which Emerson answered "very soon." After the Spanish–American War Puerto Rico was annexed by the United States under the terms of the Treaty of Paris of 1898, ratified on December 10, 1898. The United States established a military government and appointed Major General Nelson A. Miles, the first head of the military government, established on the island, acting as both head of the army of occupation and administrator of civil affairs. Many Puerto Ricans, among them Maldonado, believed that Puerto Rico would 
Title: Rafael Carrión Sr.
Content:  Banco Popular de Puerto Rico can trace its roots to 1893, when Puerto Rico was still a Spanish colony. That year, fifty-two stockholders provided the initial capital to establish the Sociedad Anonima de Economias y Prestamos ( The Anonymous Savings & Loan Society), a savings bank for the poor. However the United States invaded Puerto Rico during the Spanish–American War in 1898, and the island was annexed by the U.S. under the terms of the Treaty of Paris of 1898 which was ratified on December 10, 1898. Almost immediately, the United States began the "Americanization" process of Puerto Rico. The U.S. occupation brought about a total change in Puerto Rico's economic and political life. Amongst the many industries appropriated and controlled by the U.S. Government, were Puerto Rico's financial and banking institutions. In 1913, the United States Congress 
Title: Puerto Rico
Content:  Recent research suggests that the U.S. did consider Puerto Rico valuable as a naval station, and recognized that it and Cuba generated lucrative crops of sugar, a valuable commercial commodity which the United States lacked prior to the development of the sugar beet industry in the United States. On 25 July 1898, during the Spanish–American War, the U.S. invaded Puerto Rico with a landing at Guánica. After the U.S. prevailed in the war, Spain ceded Puerto Rico, along with the Philippines and Guam, to the U.S. under the Treaty of Paris, which went into effect on 11 April 1899; Spain relinquished sovereignty over Cuba, but did not cede it to the U.S.
Title: Stateside Puerto Ricans
Content:  came to the mainland. Since 1898, Puerto Rico has been an "insular possession" and "unincorporated territory" of the United States, ruled for its first half-century by American generals and non-Puerto-Rican civil servants from the mainland, fueling migratory patterns between the mainland and the island. After the end of the Spanish–American War a significant influx of Puerto Rican workers to the US began. With its 1898 victory, the United States acquired Puerto Rico from Spain and has retained sovereignty since. The 1917 Jones–Shafroth Act made all Puerto Ricans US citizens, freeing them from immigration barriers. The massive migration of Puerto Ricans to the mainland United States 
Title: Puerto Ricans in World War I
Content:  Puerto Ricans and people of Puerto Rican descent have participated as members of the United States Armed Forces in every conflict in which the United States has been involved since World War I. One of the consequences of the Spanish–American War was that Puerto Rico was annexed by the United States in accordance with the terms of the Treaty of Paris of 1898, ratified on December 10, 1898. On January 15, 1899, the military government changed the name of Puerto Rico to Porto Rico (On May 17, 1932, the U.S. Congress changed the name back to "Puerto Rico"). On March 21, 1915, the first shots by the United States in 
Title: Isabel González
Content:  Under the terms of the Treaty of Paris of 1898 which was ratified on December 10, 1898, Puerto Rico was annexed by the United States after the 1898 Spanish–American War. Spain had lost its last colony in the Western Hemisphere. The United States established a military government which acted as both head of the army of occupation and administrator of civil affairs. Almost immediately, the United States began the "Americanization" process of Puerto Rico. The U.S. occupation brought about a total change in Puerto Rico's economy and polity and did not apply democratic principles in their colony. Puerto Rico was classified as an "unincorporated territory" which meant that the protections of the United States Constitution — 

Question: when did the united states acquired puerto rico?
Answer: 1898.