The U.S. Supreme Court case John Horstmann Company v. United States in 1921 revolved around a dispute over customs duties on imported goods. The John Horstmann Company, an importer of umbrella materials, argued that the items should be classified under paragraph 399 of the Tariff Act of October 3rd, 1913 as "manufactures of metal not specially provided for," which would result in lower import taxes than if they were categorized as “finished” articles ready for use by consumers. However, the government contended that these imports fell under paragraph 428 and were subject to higher duty rates because they were finished products intended for direct consumer use without further manufacturing processes needed. The court ruled against John Horstmann Company stating that even though some assembly was required after importation (such as attaching handles), this did not constitute significant enough manufacturing to warrant classification under paragraph 399 with its lower tax rate. Therefore, it upheld the decision made by Customs officials and affirmed their right to classify such items according to their judgment based on existing tariff laws.

In the dissenting opinion for the case of John Horstmann Company v. United States, Justice McReynolds disagreed with the majority's ruling that a patent infringement claim could be dismissed without trial based on an administrative decision by a government agency (in this case, the U.S. Patent Office). He argued that such dismissal violated due process rights under the Fifth Amendment because it denied litigants their day in court to present evidence and arguments before an impartial judge or jury. Furthermore, he contended that allowing administrative agencies to make final determinations on legal issues would undermine judicial independence and authority. Thus, he believed that even if there was substantial evidence supporting the Patent Office's findings of fact regarding non-infringement or invalidity of patents, these should not preclude courts from conducting their own independent review through full trials.