Puerto Rico's first governor, appointed in 1509, was Spanish explorer Juan Ponce de León. He named a city on the island Puerto Rico, or "rich port," which later became the name by which the entire island was identified. Universal History Archive/UIG via Getty Images

People fill pails with water at the Christopher Columbus Fountain in Aguadilla, Puerto Rico, in 1920. Here, Columbus is said to have stepped on the shore and taken his first American drink. Bettmann Archive/Getty Images

Puerto Ricans have been US citizens since 1917, and the island has been a US commonwealth since 1952. Puerto Rico wrote its own constitution, which was approved by Congress and signed by President Harry S. Truman. Bettmann Archive/Getty Images

Puerto Ricans last voted on the question of statehood in 2017 . In the nonbinding referendum, 97% of the votes favored statehood, but voter participation was just 23% after opposition parties called for a boycott. Congress, the only body that can approve new states, will ultimately decide whether the status of the US commonwealth changes. Ricardo Arduengo/AP

A woman leaves a voting station after casting her ballot in the June 2008 Democratic presidential primary between Hillary Clinton and Barack Obama in San Juan. Puerto Ricans can vote in US primaries but not in presidential elections. ROBYN BECK/AFP/Getty Images

Tourism is big business throughout the island and pulls in about $4 billion annually. The Castillo San Cristóbal in San Juan is a top attraction. It's one of the largest fortresses built in the Americas, constructed to protect the island from military attack. Erika P. Rodriguez/Bloomberg via Getty Images

The Zika epidemic presented a threat to the health of Puerto Ricans as well as a blow to the island's tourism industry. While the crisis was declared over in June 2017, more than 35,000 cases were reported there in 2016, and a public health emergency was enacted. Here, Michelle Flandez holds her son Inti Perez, diagnosed with microcephaly linked to the mosquito-borne virus. Carlos Giusti/AP/File

Puerto Rican identity has played a prominent role in popular culture and entertainment. Hip-hop and breakdancing grew out of a multicultural New York landscape that included African-American and Puerto Rican youths. Here, a production of "West Side Story" features the fleet-footed Puerto Rican Sharks gang. Robbie Jack/Corbis via Getty Images

Prominent Puerto Ricans include Supreme Court Justice Sonia Sotomayor, playwright Lin-Manuel Miranda, pictured, actor Benicio Del Toro and entertainer Jennifer Lopez. Jordan Strauss/Invision/AP/File