William R. Day
William R. Day was an influential figure in American law, serving as an Associate Justice of the Supreme Court from 1903 to 1922. Born in Ohio in 1849 into a family with a judicial background, Day pursued a legal career, establishing a law practice and befriending prominent political figures, including President William McKinley. Appointed to the Supreme Court by McKinley's successor, Theodore Roosevelt, Day became a key supporter of antitrust policies, playing a crucial role in landmark cases such as Northern Securities Co. v. United States, where he cast the decisive vote in favor of government regulation of monopolies. His judicial philosophy demonstrated a complex relationship with economic rights, as he upheld some state regulations while often striking down federal ones. Day is also noted for his opinions in significant cases like Weeks v. United States, which established the federal exclusionary rule, and Hammer v. Dagenhart, where he controversially ruled against the Keating-Owen Child Labor Act. Despite facing declining health in his later years, Day's legacy is marked by his contributions to shaping early 20th-century legal principles related to economic regulation and individual rights.
On this Page
Subject Terms
William R. Day
Nominated by: Theodore Roosevelt
Significance: The first of President Theodore Roosevelt’s Supreme Court appointees, Day supported antitrust regulation and state power to regulate economic rights. In his most important opinion, he struck down the Keating-Owen Child Labor Act (1916).
Born in Ohio in 1849, Day was descended from a family of judges. His grandfather and father served as justices on state supreme courts. Day followed in their footsteps, graduating from law school and running his own law practice. During his law career, he became friends with the Republican governor, William McKinley. When McKinley was elected president, he appointed Day to the State Department. McKinley’s successor, Theodore Roosevelt, was soon faced with his first Supreme Court appointment and searched for a judge who would favor his antitrust policies. He settled on Day.



The justice did not disappoint him. In the first important antitrust case for the administration, Northern Securities Co. v. United States (1904), Day provided the critical fifth vote in support of the government’s prosecution of the company. Throughout his career, the justice consistently supported government regulation of monopolies.
Day was also a swing vote on the critical legal issue of the day, economic rights. Although he was willing to uphold some state economic regulations, he consistently voted to strike down federal economic regulations. It was these contradictory beliefs that placed Day on different sides of important cases during his Court tenure. For example, Day dissented in Lochner v. New York (1905), where the Court struck down a state workday maximum-hour law as a violation of liberty of contract. He also disagreed with the Court’s decision in Coppage v. Kansas (1915), in which a five-member majority struck down a state law prohibiting antiunion employment contracts.
Day did vote to limit federal power in prosecutions. He authored the Court’s opinion in Weeks v. United States (1914). In Weeks, the Court created the federal exclusionary rule, which prohibited the use of any evidence in trial if that evidence had been obtained in violation of the Fourteenth Amendment. The exclusionary rule was used by subsequent Courts to overturn convictions in federal and state cases.
Day is probably best known for his opinion in Hammer v. Dagenhart (1918). In Hammer, Day wrote for a narrow majority in striking down the Keating-Owen Child Labor Act of 1916. The act prohibited the shipment across state lines of products made by children under the age of fourteen. Day stated that the regulation intruded upon the state power to regulate labor.
After the Hammer decision, Day served as a justice for four more years, but old age and ill health made him a less productive member of the Court. By 1922 he had become unable to complete his duties and, after consultation with his colleagues, decided to resign.
Bibliography
Bader, William H., and Roy M. Mersky, eds. The First One Hundred Eight Justices. Buffalo, N.Y.: William S. Hein, 2004.
Baker, Liva. The Justice from Beacon Hill. New York: HarperCollins, 1994.
Bickel, Alexander, and Benno Schmidt. Judiciary and Responsible Government. New York: Macmillan Press, 1984.
Ely, James W., Jr. The Fuller Court: Justices, Rulings, and Legacy. Santa Barbara, Calif.: ABC-Clio, 2003.
Friedman, Leon, and Fred L. Israel, eds. The Justices of the United States Supreme Court: Their Lives and Major Opinions. 5 vols. New York: Chelsea House, 1997.
Renstrom, Peter G. The Taft Court: Justices, Rulings, and Legacy. Santa Barbara, Calif.: ABC-Clio, 2003.
Shoemaker, Rebecca S. The White Court: Justices, Rulings, and Legacy. Santa Barbara, Calif.: ABC-Clio, 2004.