The Jones–Shafroth Act, officially known as the Jones Act of 1917, was a significant piece of legislation signed into law by President Woodrow Wilson that extended United States citizenship to the residents of Puerto Rico. Prior to this, Puerto Ricans were considered subjects of the United States but did not enjoy full democratic rights. This act was monumental not only for the individuals living in Puerto Rico but also set a precedent for future relations between the United States and its territories. Among its provisions, the act allowed for the election of a bicameral legislature, which was a step towards greater local autonomy for Puerto Rico.

One of the underlying motivations for this legislative change was the strategic importance of Puerto Rico, particularly with the United States entering World War I. To bolster recruitment for the military and ensure loyalty among the Puerto Rican population, the U.S. government recognized the need to grant full citizenship. As a result, many Puerto Ricans enlisted to serve in the military during the war, demonstrating their commitment to the U.S.

Moreover, the act had lasting effects on the political landscape of Puerto Rico. It allowed for the establishment of more significant local governance, although it did not provide complete independence. The law continued to shape social, economic, and political development within Puerto Rico for decades following its enactment, affecting everything from education to civil rights.