Slawson v. United States was a Supreme Court case that addressed the issue of whether a patentee of a machine could sue for damages for the unauthorized use of the machine. The plaintiff, Slawson, was the patentee of a machine for making paper bags. He alleged that the defendant, the United States, had used the machine without his permission. The Supreme Court held that Slawson was entitled to damages for the unauthorized use of his machine. The Court reasoned that the patentee had a right to exclude others from using the machine, and that the unauthorized use of the machine constituted a violation of that right. The Court further held that the patentee was entitled to damages for the unauthorized use of the machine, even if the defendant had not acted in bad faith. The Court noted that the patentee was entitled to compensation for the value of the use of the machine, and that the damages should be determined by the jury. In conclusion, the Supreme Court held that Slawson was entitled to damages for the unauthorized use of his machine. The Court reasoned that the patentee had a right to exclude others from using the machine, and that the unauthorized use of the machine constituted a violation of that right. The Court further held that the patentee was entitled to damages for the unauthorized use of the machine, even if the defendant had not acted in bad faith.

In Slawson v. United States, the Supreme Court was asked to decide whether a federal statute that allowed for the sale of public lands in certain states and territories applied to land located within Indian reservations. The majority opinion held that it did not apply, as Congress had not explicitly stated its intention to include such lands in the legislation. Justice Field dissented from this decision, arguing that Congress had intended for all public lands subject to disposal under existing laws at the time of passage of this act should be included regardless of their location on an Indian reservation or elsewhere. He further argued that if Congress wished otherwise they would have made explicit mention thereof in their language; since they did not do so he concluded there was no reason why these particular parcels should be excluded from being sold off by virtue of their location on an Indian reservation.