In the end, most Puerto Rican citizens residing in the island acquired U.S. citizenship by simply doing nothing.

It has been 101 years since the citizens of Puerto Rico were collectively naturalized as U.S. citizens under the Jones Act of 1917. The act was meant to deal with the fact that Puerto Rico was neither a U.S. state nor an independent country. “It was foreign to the United States in a domestic sense,” said a 1901 Supreme Court decision.