by the Jones–Shafroth Act in 1917; subsequently, the U.S. Congress passed a law (signed by President Truman in 1947) which expressly extended this constitutional clause to the U.S. citizens in the jurisdiction of Puerto Rico: The rights, privileges, and immunities of citizens of the United States shall be respected in Puerto Rico to the same extent as though Puerto Rico were a State of the Union and subject to the provisions of paragraph 1 of section 2 of article IV of the Constitution of the United States. In the 1970s the Supreme Court began to recognize the application to Puerto Rico of several Constitutional protections contained in the Bill of Rights. In its opinions, the Court, without elaborating, relied on the insular cases of Downes and Balzac as precedent for the application of these constitutional rights. Footnotes Bibliography Farber, Daniel A.; Eskridge, William N., Jr.; Frickey, Philip P. Constitutional Law: Themes for the Constitution's Third Century. Thomson-West Publishing, 2003. Hall, Kermit L. ed. The Oxford Companion to the Supreme Court of the United States, Second Edition. Oxford University Press, 2005. Rich, William J. "Why 'Privileges or Immunities'? An Explanation of the Framers' Intent," Akron Law Review, 42 (no. 4, 2009), 1111–27. See also Privileges or Immunities Clause Baldwin v. Fish and Game Commission of Montana Sohappy v. Smith External links The Founders’ Constitution provides source materials regarding the original meaning of the Privileges and Immunities Clause. Findlaw describes case law relevant to the Privileges and Immunities Clause. Article Four of the United States Constitution Clauses of the United States Constitution