What are the facts?
In 1903, Oregon enacted a statute providing that no female should be employed in any mechanical establishment, factory, or laundry for more than ten hours in any one day. Curt Muller owned the Grand Laundry in Portland. He was charged and convicted of violating the statute for requiring a female employee to work more than ten hours in a single day. Muller challenged the law as an unconstitutional infringement on the liberty of contract protected by the Fourteenth Amendment's Due Process Clause, invoking the Supreme Court's recent decision in Lochner v. New York, which had invalidated a maximum-hours law for bakers as lacking a sufficient connection to health. Oregon defended its statute as a valid exercise of the police power to protect the health and welfare of women workers, submitting a brief by Louis D. Brandeis that compiled extensive social science, economic, and medical data on the deleterious health effects of long working hours on women and consequent societal impacts.
What is the legal issue?
Does an Oregon statute limiting women to a maximum of ten hours of work per day in certain industries unconstitutionally interfere with freedom of contract under the Fourteenth Amendment, or is it a valid exercise of the state's police power to protect health and welfare?
What rule applies?
Under the state's police power, a law that reasonably relates to the protection of health, safety, and welfare may limit contractual freedom without violating the Due Process Clause. In evaluating maximum-hours regulations, the Court will consider the nature of the occupation and the class of workers affected; where real differences exist that bear on health and welfare—here, the recognized physical differences and maternal functions of women—sex-specific maximum-hours laws may be sustained as reasonable health measures.
What did the court hold?
The Oregon law limiting women to a ten-hour workday in specified industries is constitutional as a reasonable health regulation under the state's police power; Muller's conviction was affirmed.
What is the reasoning?
Writing for a unanimous Court, Justice Brewer acknowledged the Lochner principle that the Fourteenth Amendment protects liberty of contract but emphasized that this liberty is not absolute and must yield to reasonable health and welfare regulations. The Court analogized to Holden v. Hardy, which upheld maximum hours for miners due to particular health hazards, and distinguished Lochner on the ground that bakers did not occupy a class whose health risks from hours were sufficiently established. The Court accepted the premise—supported in the Brandeis Brief's legislative facts—that women's "physical structure" and "maternal functions" render them more susceptible to the harms of long working hours, and that these harms implicate not only individual health but broader social interests in the wellbeing of future generations. It also reasoned that women's comparatively limited bargaining power in the labor market warranted special protection. On these grounds, the Court held the ten-hour limitation to be a reasonable, narrowly targeted health measure in factories, mechanical establishments, and laundries, rather than an impermissible interference with contract. While acknowledging potential economic burdens, the Court prioritized the state's interest in protecting women's health and the public welfare over unfettered contractual freedom. The opinion thus rested on two pillars: (1) deference to states' police powers where a clear nexus exists between the regulation and health, and (2) acceptance of sex-based distinctions where the legislature relied on empirical materials and widely held social understandings of the time regarding women's physical differences and societal roles.
Why is this case significant?
Muller is significant for three reasons. First, it marks a prominent departure from the strict Lochner-era protection of contractual liberty by recognizing broad state authority to enact health-driven labor protections. Second, it pioneered the use of empirical "legislative facts" in constitutional adjudication through the Brandeis Brief, influencing how lawyers and courts incorporate social science in constitutional cases. Third, it exposes the limits and risks of protective labor jurisprudence: the Court's endorsement of sex-based paternalism later collided with modern sex equality principles under the Equal Protection Clause and statutory antidiscrimination regimes. While Muller paved the way for upholding some labor protections (and foreshadowed decisions like Bunting v. Oregon and West Coast Hotel v. Parrish), its sex-specific rationale was undermined by later cases such as Reed v. Reed, Frontiero v. Richardson, Craig v. Boren, and United States v. Virginia, and by statutes like Title VII of the Civil Rights Act of 1964.
What is the Brandeis Brief and why was it important in Muller?
The Brandeis Brief, filed by Louis D. Brandeis for Oregon, compiled extensive social science, medical, and economic data to show the health harms of long working hours for women. It shifted appellate advocacy away from purely doctrinal argument toward empirical support for legislative judgments, and the Court explicitly relied on these legislative facts. This method influenced future constitutional litigation across subject areas.
How did Muller relate to Lochner v. New York?
Lochner struck down a maximum-hours law for bakers as an unjustified interference with freedom of contract. Muller distinguished Lochner by emphasizing women's distinct health concerns and maternal functions, accepting that the state's police power could validly limit women's working hours as a health measure. Thus, Muller functioned as an exception within the Lochner era, sustaining a labor regulation due to the class affected.
Is Muller still good law today?
Muller's core holding that states may regulate working hours under the police power remains consistent with modern deference to economic regulation. However, its sex-based rationale—that women require special protection due to inherent physical differences and maternal roles—has been repudiated by modern equal protection doctrine, which applies at least intermediate scrutiny to sex classifications (e.g., Craig v. Boren) and rejects laws based on overbroad gender stereotypes (e.g., United States v. Virginia).
What later cases built on or limited Muller?
Bunting v. Oregon (1917) upheld general maximum-hours laws applicable to all workers, signaling broader acceptance of hours regulation. Adkins v. Children's Hospital (1923) later struck down a women-only minimum wage, but West Coast Hotel v. Parrish (1937) overruled Adkins and embraced deference to wage and hour laws. Modern equal protection cases—Reed v. Reed, Frontiero v. Richardson, Craig v. Boren, and United States v. Virginia—undercut Muller's sex-specific logic.
What standard of review did the Court apply in Muller?
The Court did not use modern tiers of scrutiny. Instead, it applied a deferential reasonableness test under the police power, asking whether the regulation bore a real and substantial relation to health and welfare. It credited empirical materials about women's health and roles to find the law reasonable. Today, economic regulation typically receives rational basis review, while sex classifications receive intermediate scrutiny.