In the 1918 case of Nicoulin v. O'Brien, the U.S Supreme Court ruled on a dispute involving an inheritance tax. The plaintiff, Nicoulin, was a French citizen who inherited property in Illinois from his deceased brother. However, he faced issues when trying to transfer this property due to an Illinois law that imposed additional taxes on non-resident aliens inheriting real estate within its borders unless their home country had a reciprocal agreement with the United States not to impose similar taxes. Nicoulin argued that this law violated both the Equal Protection Clause and Due Process Clause of the Fourteenth Amendment as well as international treaties between France and America. The court disagreed with him though; it upheld Illinois' right to levy such taxes under its sovereign power over taxation matters within state boundaries. The court also found no violation of equal protection or due process rights because these clauses do not guarantee absolute equality but rather reasonable classification for legitimate government purposes - which includes raising revenue through taxation. As for treaty violations, they concluded that there were none since existing agreements did not specifically prohibit such state-level actions.

In the dissenting opinion for Nicoulin v. O'Brien, Justice Holmes disagreed with the majority's decision to uphold a Massachusetts law that prohibited foreign language instruction to children under 16. He argued that this law was an infringement on personal liberty and violated the Fourteenth Amendment’s due process clause. Holmes believed there was no compelling state interest in banning foreign languages from being taught to young students, as it did not pose any harm or threat to society or public welfare. Furthermore, he contended that such laws were based on prejudice against foreigners and their cultures rather than rational legislative judgment. In his view, parents should have the right to decide what is best for their child's education without government interference unless there is a clear danger posed by their choices.