In the United States v. Phellis case of 1921, the Supreme Court ruled on a matter concerning customs duties. The defendant, Phellis, had imported merchandise from Canada into the U.S., and was charged with paying import duties based on its value at the time it left Canada. However, he argued that this was unfair as his goods had increased in value during transit due to market fluctuations and thus he should be taxed only for their original worth when they were shipped out of Canada. The court disagreed with Phellis's argument stating that according to section 21 of Customs Administrative Act (June 10th, 1890), dutiable value is determined by "the actual market value or wholesale price" at which such or similar items are sold in usual wholesale quantities at time and place of exportation to US where shipment is destined for direct importation into US or if not so sold then same conditions but nearest practicable preceding date". Therefore, any increase in cost while en route does not affect duty charges since these are calculated based on values before departure from exporting country.

In the dissenting opinion for United States v. Phellis, 1921, Justice Holmes disagreed with the majority's decision to uphold a conviction under the Espionage Act of 1917. He argued that there was insufficient evidence to prove that Phellis had intended to obstruct recruitment and enlistment services during World War I as required by law. Furthermore, he contended that merely expressing disapproval or criticism of war should not be considered criminal activity unless it directly incites disobedience or resistance among soldiers or potential recruits. In his view, such an interpretation would infringe upon freedom of speech rights protected by the First Amendment. Thus, he believed that Phellis' conviction should have been overturned due to lack of clear proof regarding intent and direct causation between his actions and any alleged obstruction.