In the 1907 case National Life Insurance Company of the United States of America v. National Life Insurance Company, a dispute arose over trademark infringement and unfair competition. The plaintiff, an insurance company based in Vermont that had been using its name since 1848, sued another insurance company from Illinois which started operating under a similar name in 1896. The Supreme Court ruled in favor of the plaintiff stating that it was not necessary to prove fraudulent intent on part of the defendant for this kind of violation; it was enough if there existed a likelihood for confusion or deception among customers due to similarity between names. Therefore, even though both companies were licensed only within their respective states with no geographical overlap in operations at that time, potential future expansion could lead to customer confusion and hence constituted as unfair competition.

The dissenting opinion in the case of National Life Insurance Company of the United States v. National Life Insurance Company argued that there was no substantial evidence to support a claim of trademark infringement or unfair competition. The justice contended that both companies operated in different states with distinct clientele, and therefore, it would be unlikely for consumers to confuse one company for another based on their similar names alone. Furthermore, he pointed out that 'National Life' is a generic term used by many insurance companies across the country and cannot be monopolized by any single entity under trademark law principles. Thus, he disagreed with the majority's decision to grant an injunction against the defendant company from using its name within certain territories where plaintiff operates.