Puerto Rico is the largest of the United States insular areas, both as to land area and population. It is also one of the oldest in terms of being part of the United States, having been acquired along with Guam in 1899 as a result of the Spanish American War.
The Foraker Act of 1900 established a civil government for Puerto Rico. Therefore, Puerto Rico has been an "organized" TERRITORY almost from the beginning of its affiliation with the United States. However, in Downes v. Bidwell (1901) the Supreme Court held that Puerto Rico had not been incorporated into the United States. Thus, Puerto Rico was deemed to be an "unincorporated" territory. Consequently, not all portions of the U.S. Constitution were applicable there. The Jones Act of 1917 granted even more autonomy to Puerto Rico and, importantly, granted all persons born there United States CITIZENSHIP. Nonetheless, in the 1922 case of Balzac v. Porto Rico (1922), the Court held that Puerto Rico was still an unincorporated territory. (For unknown reasons, Puerto Rico was spelled "Porto Rico" in the English language version of the Treaty of Paris of 1899, the treaty that ended the Spanish American War. "Porto Rico" remained the official spelling until 1932.)
In 1950, Congress passed Public Law 600, the effect of which was to repeal portions of the Jones Act, and to rename the remainder the "Federal Relations Act." Public Law 600 authorized the people of Puerto Rico to adopt a constitution and, significantly, contained language stating that the law was "adopted in the nature of a compact." Thereafter, Puerto Rico was deemed to be in a unique relationship with the United States, known in English as a "commonwealth."
An early case, Mora v. Mejias (1953), held that the compact is inalterable without the consent of the people of Puerto Rico and that the U.S. Constitution does not apply to Puerto Rico because Puerto Rico is sovereign. Subsequently, the Court held on more than one occasion?including Harris v. Rosario (1980) and Califano v. Gautier Torres (1978)?that Congress has plenary power to...