Thatcher v. Rockwell was a United States Supreme Court case that addressed the issue of whether a patentee could sue for damages for infringement of a patent after the patent had expired. The plaintiff, Thatcher, had obtained a patent for a machine for making nails. The defendant, Rockwell, had manufactured and sold a similar machine after the patent had expired. The Supreme Court held that the patentee could not sue for damages for infringement of a patent after the patent had expired. The Court reasoned that the patentee had already received the benefit of the patent during the term of the patent, and that the patentee could not receive a double benefit by suing for damages after the patent had expired. The Court also noted that the patentee had the opportunity to sue for damages during the term of the patent, and that the patentee had not done so. The Court's decision in Thatcher v. Rockwell established that a patentee cannot sue for damages for infringement of a patent after the patent has expired. This decision has been cited in numerous subsequent cases, and has become an important precedent in patent law.

Justice Field delivered the dissenting opinion in Thatcher v. Rockwell, arguing that the majority's decision was incorrect and should be reversed. He argued that the plaintiff had a valid claim to title of land under an 1841 patent from Congress, which granted him exclusive rights to it. The defendant had acquired title through adverse possession, but Justice Field contended this did not invalidate the plaintiff's original claim as he still held legal title at the time of his death and could have passed it on to his heirs if he so chose. Furthermore, even though there were discrepancies between what was stated in both patents issued by Congress for this particular piece of land - one granting exclusive right while another allowing multiple claimants - Justice Field believed these issues should have been resolved by a court rather than dismissed outright without consideration for their potential implications on other cases involving similar circumstances. Ultimately, he concluded that since no evidence existed showing any intention or agreement among all parties involved regarding abandonment or relinquishment of ownership rights over said property prior to its acquisition by defendant via adverse possession; therefore such action cannot be used as grounds for dismissal against plaintiff’s rightful claims over same parcel of land according to law established within United States jurisdiction at present time.