In Lonergan v. United States (1937), the Supreme Court ruled on a dispute over land ownership in Texas between private citizen, John Lonergan and the U.S. government. The case revolved around whether or not an 1860 act by Congress granting lands to railroads included mineral rights beneath those lands. In this instance, oil was discovered under the disputed property which had been sold to Mr. Lonergan after being initially granted to a railroad company by Congress. The court held that when public lands are conveyed with no reservation or exception of minerals within them, it is presumed that everything necessary for their use is also transferred unless there's clear intent expressed otherwise; hence ruling in favor of Mr.Lonergan as there was no explicit mention about mineral rights in the original grant from Congress to the railroad company. This decision set precedent regarding interpretation of federal land grants and clarified that such grants should be interpreted broadly including all valuable resources unless specifically excluded.

In the dissenting opinion for Lonergan v. United States, Justice McReynolds disagreed with the majority's interpretation of contract law and its application to this case. He argued that there was a valid contract between Mr. Lonergan and the government because both parties had agreed on essential terms: price, quantity, quality of goods (land), and time/place of delivery. The only thing left open was acceptance by Mr. Lonergan which he did through his actions - paying for land sight unseen based on government descriptions in advertisements - showing intent to accept offer as is without further negotiations or need for additional information from seller (government). Therefore, according to traditional principles of contract law where an agreement can be inferred from conduct/actions if not explicitly stated in words/writing, there should have been a binding sales agreement here enforceable against seller/government when it tried later to back out after discovering it could get higher price elsewhere.