Garnharts v. United States was a case heard by the United States Supreme Court in 1873. The case involved a dispute between the United States and the Garnharts, a family of German immigrants who had settled in the United States in 1854. The United States had brought suit against the Garnharts for failing to pay taxes on certain lands they had purchased in 1854. The Garnharts argued that they were exempt from taxation under the terms of a treaty between the United States and Prussia, which had been in effect at the time of their purchase. The Supreme Court ultimately ruled in favor of the United States, finding that the treaty did not exempt the Garnharts from taxation. The Court reasoned that the treaty only applied to lands owned by Prussian citizens, and since the Garnharts were not Prussian citizens at the time of their purchase, they were not entitled to the treaty's protections. The Court also noted that the treaty had expired in 1867, and thus was no longer in effect. In conclusion, the Supreme Court ruled that the Garnharts were not exempt from taxation under the terms of the treaty between the United States and Prussia, and thus were liable for the taxes they had failed to pay.

Justice Field delivered the dissenting opinion in GARNHARTS v. UNITED STATES, arguing that the majority's decision was wrongfully based on a misinterpretation of the law and its application to this case. He argued that while Congress had granted authority to tax certain items, it did not grant them power to impose taxes on all property owned by citizens of the United States. In this particular case, he believed that there was no legal basis for taxing Garnhart’s personal property as it was not used for any commercial purpose nor did it produce income or profits from which a tax could be imposed. Furthermore, Justice Field argued that such taxation would violate due process since Garnhart had already paid taxes on his real estate and other tangible assets and thus should not have been subject to double taxation without just cause or reason. Finally, he concluded by stating that if Congress wished to extend their powers of taxation beyond what is authorized by law then they must do so through an amendment rather than relying upon judicial interpretation alone.