ABSTRACT
In Allgeyer v. Louisiana, 165 US 578, a unanimous US Supreme Court established the doctrine of "liberty of contract." Like most constitutional doctrines, liberty of contract—or the Allgeyer doctrine, as it became known—had a lineage predating its formal articulation. American judges amplified the concept of due process beyond only procedural matters to include a substantive limitation against arbitrary government action. The specific sources of such substantive limitations remained vague, with US courts referring variously to the character of legislatures, to natural-law principles, or to the common law, primarily to insulate the private ordering of economic relations-contracts and property rights-from government regulation. The specific liberty-of-contract doctrine articulated in the Allgeyer-Lochner-Adair decisions ultimately was rejected by the Supreme Court in 1937. The underlying notion that due process imposed sub-stantive as well as formal limitations on government remained viable.
