The case of Frank C. Stettler v. Edwin V. O'Hara et al., 1916, revolved around the constitutionality of a law in Oregon that set minimum wages for women and minors to protect their health, safety, and morals. The plaintiff, Stettler who was an employer argued that this law violated his rights under the Fourteenth Amendment's due process clause by interfering with freedom of contract between employers and employees. However, the Supreme Court upheld Oregon’s minimum wage law stating it did not violate any constitutional provisions as it fell within the state's police power to regulate economic activities in order to promote public welfare. This decision marked a significant shift from previous rulings where similar laws were struck down on grounds they interfered with contractual freedoms.

In the dissenting opinion for Stettler v. O'Hara, Justice James Clark McReynolds argued that the Oregon minimum wage law was unconstitutional because it interfered with an individual's right to freely contract labor. He believed that setting a mandatory minimum wage infringed upon this liberty and exceeded the state's police power. Furthermore, he contended that such legislation did not genuinely serve public interest or welfare but instead favored one group over another - in this case, female workers over their employers. The justice also criticized the majority decision for its broad interpretation of what constitutes "public interest," warning against potential misuse of this term to justify unwarranted government intervention in private affairs.