When Spain ceded Puerto Rico to the United States under the 1898 Treaty of Paris, Washington exploited Article IX of the agreement — breaking a historic precedent by omitting the collective naturalization guarantees that had accompanied every prior U.S. acquisition from Louisiana through Alaska.
This calculated exclusion instantly manufactured a tier of second-class American nationals, legally stranded with neither Spanish citizenship nor the protections of the U.S. Constitution. Eventually, Congress retained absolute discretion over their political future — a colonial reality later cemented when the “Insular Cases” established an unincorporated-territory status that no one has ever reversed. While residents eventually became statutory U.S. citizens via the Jones Act of 1917, they never became organically incorporated Americans. As a result, the legal and cultural distance engineered by Article IX remains the governing reality of the relationship today.
