In 1898, after 400 years of colonial rule, Puerto Rico was ceded to the U.S. after the Spanish-American War. Puerto Ricans were granted U.S. citizenship in 1917. Governors have been popularly elected since 1948. In 1952, a constitution was proclaimed for internal self-government.
According to QuickFacts, the population estimate for Puerto Rico was 3,195,153 on July 1, 2018, a decline of 14.3% from the 2010 Census on April 1, 2010.
From the Central Intelligence Agency, The World Factbook: Puerto Rico
“Populated for centuries by aboriginal peoples, the island was claimed by the Spanish Crown in 1493 following Christopher Columbus’ second voyage to the Americas. In 1898, after 400 years of colonial rule that saw the indigenous population nearly exterminated and African slave labor introduced, Puerto Rico was ceded to the US as a result of the Spanish-American War. Puerto Ricans were granted US citizenship in 1917. Popularly elected governors have served since 1948. In 1952, a constitution was enacted providing for internal self-government. In plebiscites held in 1967, 1993, and 1998, voters chose not to alter the existing political status with the US, but the results of a 2012 vote left open the possibility of American statehood. Economic recession on the island has led to a net population loss since about 2005, as large numbers of residents moved to the US mainland. The trend has accelerated since 2010; in 2014, Puerto Rico experienced a net population loss to the mainland of 64,000, more than double the net loss of 26,000 in 2010. Hurricane Maria struck the island on 20 September 2017 causing catastrophic damage, including destruction of the electrical grid that had been crippled by Hurricane Irma just two weeks before. It was the worst storm to hit the island in eight decades, and damage is estimated in the tens of billions of dollars.”