The turn of the 20th century saw state legislatures trying to better the lives of workers through progressive laws regulating working conditions. The law at issue in the Lochner case was one of these attempts. It said that bakers could work no more than 60 hours in one week.
The Supreme Court struck down the law, saying it was unconstitutional because it infringed on the right to buy and sell labor. The decision began what is called the "Lochner era" -- a 30-year period in which the Court battled state legislatures, abrogating many laws seeking to regulate working conditions. The 1937 case of West Coast Hotel v. Parrish, in which the Court reversed itself and began permitting some regulation of labor, ended the Lochner era.
198 U.S. 45 (1906)
The general right to make a contract in relation to his business is part of the liberty protected by the Fourteenth Amendment, and this includes the right to purchase and sell labor, except as controlled by the State in the legitimate exercise of its police power.
Liberty of contract relating to labor includes both parties to it; the one has as much right to purchase as the other to sell labor.
There is no reasonable ground, on the score of health, for interfering with the liberty of the person or the right of free contract, by determining the hours of labor, in the occupation of a baker. Nor can a law limiting such hours be justified a a health law to safeguard the public health, or the health of the individuals following that occupation.
Section 110 of the labor law of the State of New York, providing that no employees shall be required or permitted to work in bakeries more than sixty hours in a week, or ten hours a day, is not a legitimate exercise of the police power of the State, but an unreasonable, unnecessary and arbitrary interference with the right and liberty of the individual to contract in relation to labor, and, as such, it is in conflict with, and void under, the Federal Constitution.
This is a writ of error to the County Court of Oneida County, in the State of New York (to which court the record had been remitted), to review the judgment of the Court of Appeal of that State affirming the judgment of the Supreme Court, which itself affirmed the judgment of the County Court, convicting the defendant of a misdemeanor on an indictment under a statute of that State, known, by its short title, as the labor law. The section of the statute under which the indictment was found is section 110, and is reproduced in the margin, (together with the other sections of the labor law upon the subject of bakeries, being sections 111 to 115, both inclusive). The indictment averred that the defendant
"wrongfully and unlawfully required and permitted an employee working for him in his biscuit, bread and cake bakery and confectionery establishment, at the city of Utica, in this county, to work more than sixty hours in one week,"
after having been theretofore convicted of a violation of the same act, and therefore, as averred, he committed the crime or misdemeanor, second offense. The plaintiff in error demurred to the indictment on several grounds, one of which was that the facts stated did not constitute a crime. The demurrer was overruled, and the plaintiff in error having refused to plead further, a plea of not guilty was entered by order of the court and the trial commenced, and he was convicted of misdemeanor, second offense, as indicted, and sentenced to pay a fine of $50 and to stand committed until paid, not to exceed fifty days in the Oneida County jail. A certificate of reasonable doubt was granted by the county judge of Oneida County, whereon an appeal was taken to the Appellate Division of the Supreme Court, Fourth Department, where the judgment of conviction was affirmed. 73 App.Div.N.Y. 120. A further appeal was then taken to the Court of Appeals, where the judgment of conviction was again affirmed. 177 N.Y. 145.