The Lochner era was a period in American legal history from 1897 to 1937 in which the Supreme Court of the United States is said to have made it a common practice "to strike down economic regulations adopted by a State based on the Court's own notions of the most appropriate means for the State to implement its considered policies".[1] The court did this by using its interpretation of substantive due process to strike down laws held to be infringing on economic liberty or private contract rights.[2][3] The era takes its name from a 1905 case, Lochner v. New York. The beginning of the era is usually marked earlier, with the Court's decision in Allgeyer v. Louisiana (1897), and its end marked forty years later in the case of West Coast Hotel Co. v. Parrish (1937), which overturned an earlier Lochner-era decision.[4]
The Supreme Court during the Lochner era has been described as "play[ing] a judicially activist but politically conservative role".[5] The Court sometimes invalidated state and federal legislation that inhibited business or otherwise limited the free market, including minimum wage laws, federal (but not state) child labor laws, regulations of banking, insurance and transportation industries.[5] The Lochner era ended when the Court's tendency to invalidate labor and market regulations came into direct conflict with Congress's regulatory efforts in the New Deal.
Since the 1930s, Lochner has been widely discredited as a product of a "bygone era" in legal history.[1] Robert Bork called Lochner "the symbol, indeed the quintessence, of judicial usurpation of power".[6] In his confirmation hearings to become Chief Justice, John Roberts said: "You go to a case like the Lochner case, you can read that opinion today and it's quite clear that they're not interpreting the law, they're making the law." He added that the Lochner court substituted its own judgment for the legislature's findings.[7]