Insular Cases
The Insular Cases refer to a series of U.S. Supreme Court decisions from the early 1900s that addressed the constitutional status of territories acquired by the United States following the Spanish-American War, including Puerto Rico, Guam, and the Philippines. These cases arose amid a national debate over imperialism, with proponents arguing for the necessity of territorial expansion and opponents cautioning against the potential implications for democracy and constitutional rights. The Supreme Court's rulings established a framework whereby these territories were considered "appurtenant" to the United States but not fully incorporated, meaning that residents did not enjoy the same constitutional protections as U.S. citizens.
The Court's majority often underscored a belief that these territories were inhabited by "alien races," which influenced the justices’ decisions about the applicability of constitutional rights. The Insular Cases have since become a focal point for discussions on race, citizenship, and civil rights, particularly as they relate to U.S. territories that have not achieved statehood. Notably, the cases continue to resonate today, as seen in recent legal challenges regarding citizenship rights for residents of territories like American Samoa, highlighting ongoing debates about inclusion and equality under U.S. law.
Insular Cases
Date May 27, 1901
The US Supreme Court determined the constitutional status of overseas territories of the United States.
Locale Washington, DC
Key Figures
Henry B. Brown (1836–1913), associate justice of the United StatesMelville W. Fuller (1833–1910), chief justice of the United StatesJohn Marshall Harlan (1833–1911), associate justice of the United StatesEdward D. White (1845–1921), associate justice of the United States
Summary of Event
By the beginning of the 1900s, the United States acquired an overseas empire. Hawaii was annexed by joint resolution of both houses of Congress, and Puerto Rico, Guam, and the Philippine Islands were ceded to the United States by Spain under the terms of the Treaty of Paris, which ended the Spanish-American War. The eastern Samoan archipelago islands were also ceded to the United States beginning in 1900, becoming American Samoa with the addition of Swains Island in 1925. In a series of decisions known as the Insular Cases, the US Supreme Court was called on to fashion a constitutional compromise whereby the territorial acquisitions desired by the national political forces would be rendered legitimate.

The drive to acquire foreign territory was led by Republican chieftains such as Theodore Roosevelt and Senator Henry Cabot Lodge, whereas opponents of “imperialism” were primarily Democrats. Much of the debate focused on the question of Senate advice and consent to the peace treaty negotiated by President William McKinley with Spain. One of the chief constitutional arguments used by the opponents of expansion was the slogan “The Constitution follows the flag,” which was designed to dramatize the impractical nature of the annexation of territory that offered no prospect of being organized into states. Anti-imperialists such as Senator George O. Vest of Missouri and Senator George Hoar of Massachusetts argued that the Constitution did not give the federal government the power to acquire territories to be held permanently in subjugation as colonies. The power to acquire territories, they claimed, was inextricably connected with the responsibility to organize those territories into prospective states.
Moreover, they argued that imperialism by its very nature was contrary to the republican form of government established under the Constitution. Anti-imperialists also cited the Declaration of Independence as a general indictment of colonial arrangements. Vest made another constitutional argument against acquisition of colonies when he interpreted the Fourteenth Amendment’s declaration that “all persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States.”
The advocates of expansion contended that the success of the United States in the Spanish-American War destined the nation for a major role in world affairs and that it was naïve to postpone the acquisition of colonies. Apologists for acquisition argued that colonies would provide the growing United States with outposts essential to the nation’s security, ensure its control of the seas, and underwrite the steady growth of its burgeoning industry.
Arguments in what the Supreme Court called the Insular Tariff Cases were heard for six days in January 1901, and the court’s opinions were announced on May 27, 1901. The principles set forth at that time also determined the outcomes of two other cases that had been argued in December 1899. In DeLima v. Bidwell, the court divided five to four on the question of the application of the general tariff laws (the Dingley Tariff) to imports from Puerto Rico following the proclamation of the treaty with Spain. In stating the majority opinion, Justice Henry B. Brown said, “We are therefore of the opinion that at the time these duties were levied, Puerto Rico was not a foreign country within the meaning of the tariff laws but a territory of the United States, that the duties were illegally exacted, and that the plaintiffs are entitled to recover them back.”
In a dissenting opinion, Justice Joseph McKenna, supported by Justices George Shiras and Edward D. White, contended that Puerto Rico’s status as a foreign or nonforeign country had nothing to do with whether the tariff laws were applicable. It was clear, argued McKenna, that the island was not a part of the United States, and therefore the tariff laws should apply. Justice Horace Gray wrote a separate brief dissent.
The justices who dissented in DeLima v. Bidwell were joined by Justice Brown in the companion case of Downes v. Bidwell and, as if to dramatize the judicial confusion, Justice Brown again delivered the lead opinion. The question in Downes v. Bidwell concerned the validity of a special tariff law applicable only to Puerto Rico (the Foraker Act). Justice Brown concluded a long opinion surveying the applicable precedents and practices with the declaration that the judiciary must be careful not to impede the development of “the American Empire.” The annexation of distant possessions “inhabited by alien races, differing from us in religion, customs, laws, methods of taxation and modes of thought,” might some day be desirable. He continued:
The question at once arises whether large concessions ought not to be made for a time, that, ultimately, our own theories may be carried out, and the blessings of a free government under the Constitution extended to them. We decline to hold that there is anything in the Constitution to forbid such action.
Brown went on to rule that Puerto Rico was a “territory appurtenant and belonging to the United States, but not a part of the United States within the revenue clauses of the Constitution” and that the Foraker Act was, therefore, constitutional.
In a concurring opinion supported by Shiras and McKenna, Justice White introduced his theory of incorporation, which subsequently came to be the prevailing doctrine. According to White, “Whilst in an international sense Puerto Rico was not a foreign country, since it was subject to the sovereignty of and was owned by the United States, it was foreign to the United States in a domestic sense, because the island had not been incorporated into the United States, but was merely appurtenant thereto as a possession.” It followed from this, said White, that the constitutional requirement that duties be uniform throughout the United States was not applicable to Congress in legislating for the island. Justice Gray solitarily concurred and argued that the law was valid because Puerto Rico was in a transitional stage from conquered territory to statehood.
Chief Justice Melville W. Fuller’s dissenting opinion in Downes v. Bidwell was supported by the three justices who, along with Brown, had made up the DeLima v. Bidwell majority: John Marshall Harlan, David J. Brewer, and Rufus W. Peckham. Fuller urged that the Constitution did indeed follow the flag, that Puerto Rico was not a foreign country, and that Congress had violated the constitutional requirement that all taxes, duties, and imposts be uniform throughout the United States. Justice Harlan wrote a separate dissenting opinion that, among other things, attacked the White theory of incorporation.
Many constitutional scholars consider Harlan’s dissent to be one of the great opinions in the history of the US Supreme Court. Harlan asserted that it was not legitimate to argue, as the majority did, that Congress could take away some or any rights from territories of the United States. He held that the Constitution was in force wherever the US flag had been planted. In the case of Puerto Rico and the Philippines, that meant residents of those islands had full constitutional rights and protections from the moment the Senate ratified the treaty making them US possessions. That had been accomplished in 1899, with ratification of the treaty with Spain ending the Spanish-American War. Justice Harlan rejected the racist argument raised by some members of the court, that Filipinos and Puerto Ricans were “alien races” not covered by the Anglo-Saxon-inspired Constitution. He concluded his dissent with a warning: “The Constitution is not to be obeyed or disobeyed as the circumstances of a particular crisis in our history may suggest. . . . The People have decreed that it shall be the supreme law of the land at all times.”
The majority did not accept Harlan’s view that once a territory becomes part of the United States, its people must have all the protections enjoyed by all citizens. Residents of the new island territories were denied equal protection of the law, chiefly because they were considered to be racially inferior and unready for most democratic rights. Thus, contrary to what Harlan believed to be the ideas of the Framers of the Constitution, the court supported a policy that allowed people to be governed without their consent.
Significance
In subsequent cases dealing with the question of the Constitution’s applicability to territories, the court was presented with questions having to do with the rights of criminal defendants within the rights of constitutional guarantees. Justice Brown again employed the extension theory in Hawaii v. Mankichi (1903) in finding that Congress had not extended the guarantees of the Bill of Rights to Hawaii. It was permissible, therefore, for Hawaii to try the defendant on the basis of any information instead of a grand jury indictment and to convict him on the strength of only nine guilty votes out of a jury of twelve. On the basis of his incorporation theory, Justice White agreed with this opinion, and this time he was joined by Justice McKenna.
The next year, in Dorr v. United States, White’s incorporation theory was adopted by a court majority; it held that until the Philippines were incorporated into the United States by Congress, the latter could administer the territory under its general power to govern territory and without honoring all of the applicable constitutional guarantees. Subsequently, the court held that Alaska had been sufficiently incorporated to warrant application of the Fifth, Sixth, and Seventh Amendments; in Rasmussen v. United States (1905), the court reversed a conviction of a defendant found guilty on the basis of a six-person jury. In Dowdell v. United States (1911), the court applied the same logic but reached the conclusion that the Philippines were not incorporated; therefore, it was permissible for territorial authorities to employ juries of fewer than twelve persons. Finally, in Puerto Rico v. Tapia (1918), the court ruled that the congressional grant of citizenship to Puerto Ricans did not necessarily mean that these citizens were protected by the traditional constitutional guarantees.
Alaska and Hawaii, the two territories that the Supreme Court found to have been incorporated, became states of the Union on January 3 and August 21, 1959, respectively. The Philippines (which gained independence in 1946), Puerto Rico, Guam, and the Virgin Islands (bought from Denmark in 1917) never were incorporated, although their inhabitants were congressionally declared US citizens. Incorporation was never an issue insofar as the other minor possessions were concerned. Residents of the Northern Mariana Islands, a US unincorporated territory beginning in 1947 before becoming a commonwealth in the 1980s, also legislatively gained US citizenship. In the late 2010s, a group of three people who had been born in American Samoa but were living in the United States sued for birthright US citizenship for American Samoans, the only residents of a US unincorporated territory to still lack this full constitutional right; instead, they had been deemed US nationals. After an appeals court decided against the plaintiffs partly on the basis of the rulings from the Insular Cases, the case was appealed to the Supreme Court. Though Justice Neil Gorsuch had argued in favor of a reconsideration of the Insular Cases, which he felt were racist rather than constitutional, the Supreme Court declined in 2022 to consider the case. The government of American Samoa, meanwhile, opposed granting US birthright citizenship to those born in American Samoa.
Bibliography
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Gould, Lewis L. The Spanish-American War and President McKinley. Lawrence: University Press of Kansas, 1980.
Henkin, Louis. Foreign Affairs and the U.S. Constitution. 2d ed. New York: Oxford University Press, 1996.
Kerr, James E. The Insular Cases: The Role of the Judiciary in American Expansionism. Port Washington, N.Y.: Kennikat Press, 1982.
LaFeber, Walter. The New Empire: An Interpretation of American Expansion, 1860-1898. 35th anniversary ed. Ithaca, N.Y.: Cornell University Press, 1998.
Quinn, Melissa. "Supreme Court Turns Away Case Involving Birthright Citizenship for American Samoans." CBS News, 17 Oct. 2022, www.cbsnews.com/news/supreme-court-birthright-citizenship-american-samoa-insular-cases/. Accessed 20 Dec. 2022.
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Thompson, Winfred Lee. The Introduction of American Law in the Philippines and Puerto Rico, 1898-1905. Fayetteville: University of Arkansas Press, 1989.