Jurisprudence
During Harlan's tenure on the Supreme Court, major Supreme Court decisions tended to address issues arising from industrialization and the Reconstruction Amendments. Beginning in the 1880s, the Supreme Court increasingly began to adopt a laissez-faire philosophy, striking down economic regulations while at the same time allowing states to curtail the rights of African Americans. Harlan differed from many of his colleagues, often voting to uphold federal regulations and to protect the civil rights of African Americans. His judicial opinions were influenced by his life-long belief in a strong national government, his sympathy for the economically disadvantaged, and his view that the Reconstruction Amendments had fundamentally transformed the relationship between the federal government and the state governments. Though Harlan believed the Court had the power to review state and federal actions on a broad array of topics, he tended to oppose judicial activism in favor of deference to legislatures.
Congress had passed the Civil Rights Act of 1875 in the waning days of Reconstruction, outlawing segregation in public accommodations such as railroads. The Supreme Court did not rule on the Civil Rights Act of 1875 until 1883, when it struck down the law in Civil Rights Cases. In his majority opinion, Justice Joseph P. Bradley held that the Thirteenth Amendment "simply abolished slavery," and that the Fourteenth Amendment did not authorize Congress to bar racial discrimination by private actors. Only Harlan dissented, vigorously, charging that the majority had subverted the Reconstruction Amendments: "The substance and spirit of the recent amendments of the constitution have been sacrificed by a subtle and ingenious verbal criticism." Harlan argued that the Fourteenth Amendment gave Congress the authority to regulate public accommodations, and further argued that the Thirteenth Amendment empowered Congress to "eradicate" the vestiges of slavery, such as restrictions on freedom of movement.
Harlan joined the Court's unanimous decision in Pace v. Alabama (1883), which ruled that anti-miscegenation laws were constitutional. Harlan was the first justice to argue that the Fourteenth Amendment incorporated the Bill of Rights (making rights guarantees applicable to the individual states), in Hurtado v. California (1884). Harlan was one of four justices to file a dissenting opinion in Pollock v. Farmers' Loan & Trust Co. (1895), which struck down a federal income tax levied by the Wilson–Gorman Tariff Act of 1894. Harlan described the majority opinion as a "disaster to the country" because it "impairs and cripples the just powers of the national government". He was the sole dissenter in another 1895 case, United States v. E. C. Knight Co., in which the Court severely curtailed the power of the federal government to pursue antitrust actions under the Sherman Antitrust Act. In his dissent, he wrote that "the common government of all the people is the only one that can adequately deal with a matter which directly and injuriously affects the entire commerce of the country." During the 1890s, he also wrote several dissents in cases where Court decisions curtailed the regulatory powers of the Interstate Commerce Commission (ICC).
In 1896, Associate Justice Henry Billings Brown delivered the majority decision in Plessy v. Ferguson, which established the doctrine of "separate but equal". Whereas the Civil Rights Cases had struck down a federal law barring segregation by private actors, the Court's opinion in Plessy allowed state governments to engage in segregation. Rejecting the argument that segregation violated the Thirteenth Amendment, Brown wrote that "a statute which implies merely a legal distinction between the white and colored races has no tendency to destroy the legal equality of the two races, or reestablish a state of involuntary servitude." In response to the plaintiff's claims regarding the Fourteenth Amendment, Brown wrote that the Fourteenth Amendment was designed to "enforce the absolute equality of the two races before the law," but added that the amendment "could not have been intended to abolish distinction based upon color, or to enforce social, as distinguished from political, equality, or a commingling of the two races upon terms unsatisfactory to either".
Harlan, the lone dissenting justice, strongly disapproved of the majority opinion, writing that "the judgement this day rendered, will, in time, prove to be quite as pernicious as the decision made by this tribunal in the Dred Scott Case". He accepted the appellant's argument that the Thirteenth Amendment barred segregation in public accommodations, as he believed that segregation imposed "badges of slavery or servitude" upon African Americans. He also accepted the appellant's argument that the segregation in public accommodations violated the Fourteenth Amendment on the basis that these accommodations constituted "public highway[s]". He further wrote that "our Constitution is color-blind, and neither knows nor tolerates classes among citizens." Harlan rejected the idea that the law in question was race-neutral, writing that "everyone knows that the statute in question [was intended] to exclude colored people from coaches occupied by or assigned to white persons", adding that the law was "cunningly devised" to overturn the results of the Civil War.
Harlan did not embrace the idea of full social racial equality. While he had appeared to advocate for equality among those of different races and for a color-blind Constitution in his Plessy dissent, he also stated "[t]here is a race so different from our own that we do not permit those belonging to it to become citizens of the United States ... I allude to the Chinese race."
In United States v. Wong Kim Ark (1898), Harlan joined Chief Justice Fuller's dissent proclaiming the dangers of having large numbers of Chinese immigrants in the United States. The Court's holding was that persons of Chinese descent born in the United States were citizens by birth. Fuller and Harlan argued that the principle of jus sanguinis (that is, the concept of a child inheriting their father's citizenship by descent regardless of birthplace) had been more pervasive in U.S. legal history since independence. In the view of the minority, excessive reliance on jus soli (birthplace) as the principal determiner of citizenship would lead to an untenable state of affairs in which "the children of foreigners, happening to be born to them while passing through the country, whether of royal parentage or not, or whether of the Mongolian, Malay or other race, were eligible to the presidency, while children of our citizens, born abroad, were not".
Harlan was also the most staunchly anti-imperialist justice of the Supreme Court, arguing consistently in the Insular Cases (from 1901 to 1905) that the Constitution did not permit the demarcation of different rights between citizens of the states and the residents of newly acquired territories in the Philippines, Hawaii, Guam, and Puerto Rico, a view that was consistently in the minority. In Hawaii v. Mankichi (1903) his opinion stated: "If the principles now announced should become firmly established, the time may not be far distant when, under the exactions of trade and commerce, and to gratify an ambition to become the dominant power in all the earth, the United States will acquire territories in every direction... whose inhabitants will be regarded as 'subjects' or 'dependent peoples,' to be controlled as Congress may see fit... which will engraft on our republican institutions a colonial system entirely foreign to the genius of our Government and abhorrent to the principles that underlie and pervade our Constitution."
Harlan delivered the majority opinion in Chicago, Burlington & Quincy Railroad Co. v. City of Chicago (1897), holding that due process required fair compensation to be given for any private property seized by the state. The decision incorporated the Fifth Amendment's Takings Clause, representing the first time that part of the Bill of Rights was applied to state governments. The Court would not incorporate another provision of the Bill of Rights until Gitlow v. New York (1925). Harlan wrote the majority opinion in Northern Securities Co. v. United States, the first time the Court upheld the use of the Sherman Antitrust Act to break up a large corporation. Harlan also wrote the majority opinion in Jacobson v. Massachusetts (1905) upholding the government's right to enforce vaccination requirements, and the majority opinion in Adair v. United States (1908), holding that Congress did not have the power to ban "yellow-dog contracts".
During his final years on the Court, Harlan continued to write dissents in major cases, such as Giles v. Harris (1903), a case challenging the use of grandfather clauses to restrict voting rolls and de facto exclude blacks. He also dissented in Lochner v. New York (1905), but he agreed with the majority "that there is a liberty of contract which cannot be violated even under the sanction of direct legislative enactment". In his dissent in Hodges v. United States (1906), Harlan reiterated his belief that the Thirteenth Amendment empowered Congress to protect African Americans from discrimination and violence. He was the lone dissenter in Ex parte Young (1908), arguing that the Eleventh Amendment prevented suits against state officials acting on behalf of the state. In his partial dissent in the 1911 case of Standard Oil Company of New Jersey v. United States, Harlan argued against the Court's establishment of the rule of reason, which held that in some extenuating circumstances a trust should not be broken up even if it has a monopoly. In both Standard Oil and United States v. American Tobacco Co. (1911), Harlan strongly criticized the majority opinion for adopting the rule of reason; as the rule was not present in the original legislation, he believed that the Court was usurping Congress's legislative prerogatives.
On March 12, 1906, Harlan donated a King James Version Bible to the Supreme Court. This Bible had become known as the "Harlan Bible". As of 2015, this Bible has been signed by every succeeding Supreme Court justice after taking the oath of office.