ernment proposing to itself the development of the power of the nation at sea
Since 1894, the Naval War College had been formulating contingency plans for a war with Spain. By 1896, the Office of Naval Intelligence had prepared a plan which included military operations in Puerto Rican waters. This prewar planning did not contemplate major territorial acquisitions. Except for one 1895 plan which recommended annexation of the island then named Isle of Pines (later renamed as Isla de la Juventud), a recommendation dropped in later planning, plans developed for attacks on Spanish territories were intended as support operations against Spain's forces in and around Cuba. However, Jorge Rodriguez Beruf, recognized as a foremost researcher on United States militarism in Puerto Rico, writes that not only was Puerto Rico considered valuable as a naval station, Puerto Rico and Cuba were also abundant in sugar – a valuable commercial commodity which the United States lacked.
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, Spain ceded Puerto Rico, along with the Philippines and Guam, that were under Spanish sovereignty, to the U.S. under the Treaty of Paris. Spain relinquished sovereignty over Cuba, but did not cede it to the U.S.
The United States and Puerto Rico thus began a long-standing relationship. Puerto Rico began the 20th century under the military rule of the U.S. with officials, including the governor, appointed by the President of the United States. The Foraker Act of 1900 gave Puerto Rico a certain amount of civilian popular government, including a popularly elected House of Representatives, also a judicial system following the American legal system that includes both state courts and federal courts establishing a Puerto Rico Supreme Court and a United State District Court; and a non-voting member of Congress, by the title of "Resident
