In the case of Kingman v. Western Manufacturing Company, 1897, the U.S Supreme Court was tasked with determining whether a patent for an improvement in grain separators was valid or not. The plaintiff, Kingman & Co., alleged that Western Manufacturing Company had infringed on their patent rights by using and selling machines embodying features covered by their patents without authorization. However, the defendant argued that these patents were invalid due to lack of novelty as similar devices already existed before they were patented. After reviewing evidence from both sides including expert testimonies and prior art references (earlier inventions), the court ruled in favor of Western Manufacturing Company stating that there was no substantial difference between what is claimed in Kingman's patents and what has been previously known or used; hence it lacked novelty which is one of key requirements for obtaining a patent under US law.

In the dissenting opinion for Kingman v. Western Manufacturing Company, it was argued that the majority's decision to uphold a lower court ruling in favor of Western Manufacturing Company was incorrect. The dissenting justices believed that there were significant errors made during the trial process which should have resulted in a retrial. They pointed out inconsistencies and contradictions within witness testimonies, arguing these discrepancies raised reasonable doubt about whether Kingman had indeed infringed upon Western Manufacturing’s patent rights as claimed. Furthermore, they disagreed with how certain evidence was interpreted by both the jury and presiding judge at trial level; particularly regarding technical aspects related to machinery design and functionality - central issues in this patent dispute case. The dissenters also took issue with instructions given to jurors before deliberation commenced, suggesting they may have been misleading or confusing thereby potentially influencing their verdict unfairly against Kingman.