The U.S. Supreme Court case New Orleans Land Company v. Brott et al., 1923, revolved around a dispute over land ownership in the state of Louisiana. The New Orleans Land Company claimed that they were rightful owners of certain lands based on a grant from the Spanish government before it ceded Louisiana to France in 1800, which was later purchased by the United States through the Louisiana Purchase in 1803. However, this claim was contested by Brott and others who argued that under French law at the time of cession, grants like these were not valid unless officially registered - something which had not been done for this particular grant. The court ruled against New Orleans Land Company stating that when interpreting treaties between nations (in this case Spain's treaty with France), domestic laws are irrelevant if they contradict international agreements or customary international law principles recognized by civilized nations. Therefore, even though registration might have been required under French domestic law at that time to validate such grants; since there was no such requirement under Spanish Law or International Law during their rule over Louisiana prior to its sale to France; hence it did not apply here.

The dissenting opinion in the case of New Orleans Land Company v. Brott et al., 1923, argued that the majority's decision was inconsistent with previous rulings and principles of law. The dissent contended that a state has no power to tax lands owned by the United States unless Congress explicitly grants it such authority. In this case, there was no evidence to suggest that Congress had given Louisiana permission to impose taxes on federally-owned land located within its borders. Therefore, according to the dissenters, these taxes were unconstitutional and should have been invalidated by the court. They also expressed concern about potential implications for federal property rights across all states if local governments could unilaterally decide to levy taxes on U.S.-owned lands without congressional approval.