This report provides policy and historical background about Puerto Rico's political status —referring to the relationship between the federal government and a territorial one. Congress has not altered the island's status since 1952, when it approved a territorial constitution. Status is the lifeblood of Puerto Rican politics, spanning policy and partisan lines in ways that are unfamiliar on the mainland. Puerto Rico has been in political flux in recent years, culminating most recently in the 2017 plebiscite. Momentum toward that outcome began in the 2016 elections, when Puerto Ricans selected a prostatehood New Progressive Party (NPP/PNP) Governor, Resident Commissioner, and majorities in the Legislative Assembly. Shortly after assuming office, the Governor and legislature enacted a territorial law authorizing a plebiscite containing two ballot choices: statehood or free association/independence. (Free association is a form of independence entailing negotiated close ties between two countries.) After the U.S. Department of Justice declined to certify the release of federal funds to support the plebiscite, Puerto Rico amended its plebiscite law to add a status-quo option on the ballot. Some political parties and other groups on the island encouraged their supporters to boycott the plebiscite. On June 11, 23.0% of voters turned out for the plebiscite, where 97.2% selected statehood; 1.5% selected free association/independence; and 1.3% chose the "current territorial status." In anticipation of a statehood victory in the plebiscite, the territorial legislature enacted, and the Governor signed, legislation in June 2017 to pursue a "Tennessee Plan" path to statehood. That method traditionally involves sending an appointed or elected "delegation" to Washington to lobby Congress to grant statehood. Because the U.S. Constitution grants Congress broad discretion over territories, the House and Senate may choose to reexamine Puerto Rico's political status, or to decline to do so. If Congress chose to alter Puerto Rico's political status, it could do so through statute regardless of whether a plebiscite were held or what sentiment such a vote revealed. As with all CRS reports, this product provides background information and analysis for Congress. It emphasizes those facets of the status policy debate that historically have been most relevant for House and Senate consideration, and that appear to remain most relevant for Members and staff who are considering those issues. It emphasizes the current status debate in Puerto Rico specifically rather than examining status in all U.S. territories. This report is not intended to substitute for a comprehensive analysis of the complex and culturally sensitive issues surrounding Puerto Rico's more than 100-year affiliation with the United States. The report also is not intended to be an analysis of the various legal, economic, or social issues that might arise in considering Puerto Rico's political status or a change in its relationship with the United States. Parts of this report are adapted from another CRS product, which provides additional discussion of the 2012 plebiscite. Puerto Rico has been the subject of strategic and political attention for more than 500 years. Spain was the first colonial power to claim the island. Christopher Columbus landed on the west coast of the main island of present-day Puerto Rico on November 19, 1493. There, he encountered native Taíno Indians, who called the island "Borinquén" (or, in some spellings, "Borinkén"). As one scholar has noted, "[a] permanent foothold was finally established in 1508, when Juan Ponce León led a group of settlers from Hispaniola." Spanish colonizers forced the Taíno into servitude, and "[b]y 1521, the Indian Borinquén had become another Spanish settlement in an expanding empire." For the next 400 years, Puerto Rico served as a Spanish agricultural and mining outpost in the Caribbean. When the United States defeated Spain in the Spanish-American War (1898), the United States acquired Puerto Rico, Guam, and the Philippines from Spain via the Treaty of Paris. Puerto Rico provided the United States with a central location from which to exercise military and strategic power in the Caribbean, particularly before World War II. The U.S. military briefly administered the island until Congress established a civilian government in 1900. Today, Puerto Rico is both deeply integrated into American society and insulated from it. On one hand, the American flag has flown over San Juan, the capital, for more than 100 years. In addition, those born in Puerto Rico are U.S. citizens. Many live and work on the mainland and serve in the military. On the other hand, as shown in Figure 1 , the island is geographically isolated from the mainland United States; it lies approximately 1,500 miles from Washington and 1,000 miles from Miami. Residents of Puerto Rico lack full voting representation in Congress, typically do not pay federal income taxes on income earned on the island, do not have the same eligibility for some federal programs as those in the states, do not vote in presidential elections (although they may do so in party primaries), and enjoy a culture and predominant Spanish language that some argue more closely resembles Latin America than most of the 50 states. Some regard status as the fundamental political question that drives everything else about the Puerto Rico-U.S. relationship. Others see status as a distraction from more compelling everyday policy and economic challenges. Perhaps because that debate remains unsettled, status is an undercurrent in virtually every policy matter on the island. Federal policy debates generally are less affected by status, but here, too, status often arises at least tangentially. As such, even a basic knowledge of the topic may be helpful in multiple policy areas. In the foreseeable future, oversight of Puerto Rico is likely to be relevant for Congress as the House and Senate monitor the Puerto Rico Oversight, Management, and Economic Stability Act (PROMESA) enacted during the 114 th Congress (discussed elsewhere in this report and in other CRS products) in response to the island's financial crisis. Legislation introduced in the 115 th Congress, discussed elsewhere in this report, could affect the island's political status. In addition, the House and Senate could choose to respond to the 2017 plebiscite through oversight, legislation, or both. (Congress also could choose to take no action.) Finally, before proceeding, it is noteworthy that much of the status debate in Puerto Rico concerns attitudes surrounding past or future plebiscites. Whether in the past or future, Puerto Rico may choose to hold its own plebiscites without congressional authorization. Recently, however, plebiscite supporters have argued that federal support for a plebiscite could increase the perceived legitimacy of the results. Plebiscites are not required to revisit status. Whether or not a plebiscite were held, Congress could admit Puerto Rico as a state, or decline to do so, at its discretion, through statute. Puerto Rico is a U.S. territory subject to congressional authority derived from the Territory Clause of the U.S. Constitution. The Territory Clause grants Congress "Power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States." Congress has enacted various statutes to address specific matters concerning the island's political status. Puerto Rico's current political status, as determined by federal statute (or otherwise, as noted), is summarized briefly below. After military governance since the United States acquired Puerto Rico in 1898, Congress established a civilian government on the island in 1900. Among other points, the Foraker Act established an "executive council" consisting of a presidentially appointed civilian governor and various department heads. The new government also included a popularly elected House of Delegates (which shared decisionmaking power with the executive council) and a U.S.-style judiciary system. The Foraker Act also established the Resident Commissioner position to represent island interests in Washington. These duties came to include nonvoting service in the U.S. House of Representatives (the primary role of the Resident Commissioner today). Through the Jones Act (1917), Congress authorized appropriations for legislative staff and franking privileges for the Resident Commissioner. Devoted primarily to strengthening Puerto Rico's civil government, the Jones Act also extended U.S. citizenship to Puerto Ricans and established a bill of rights for the island. Major governmental changes included establishing a three-branch government similar to the one on the mainland. Congress recognized island authority over matters of internal governance in 1950 through the Federal Relations Act (FRA) and when it approved the island's Constitution in 1952. No major status changes have occurred since. After enactment of the FRA and approval of the territorial constitution, Puerto Rico became known formally as the "Commonwealth of Puerto Rico." Use of the word "commonwealth" and whether the term carries particular legal or political significance is a topic of substantial historical and scholarly debate—most of which is not addressed herein. A brief summary of the competing major perspectives, however, provides important context for understanding the ongoing status debate. Some contend that Puerto Rico's commonwealth status signifies a unique recognition somewhere between territory and state. This perspective is often called "enhanced commonwealth" or "new commonwealth." As longtime territories scholar Arnold H. Leibowitz has summarized, those holding this view have argued that more than local self-government was achieved by the 1950-1952 legislation. It contends that a new legal entity was created with a unique status in American law: the Commonwealth, a status which is an internationally recognized non-colonial status.... Most important, in this view, Commonwealth is not a "territory" covered by the 'Territory Clause' of the Constitution, nor quite obviously is it a state; rather, Commonwealth is sui generis and its judicial bounds are determined by a "compact" which cannot be changed without the consent of both Puerto Rico and the United States.