In Buena Vista County v. Iowa Falls & Sioux City Railroad Company, the Supreme Court of the United States was asked to decide whether a county could tax a railroad company for the value of its property. The railroad company argued that the tax was unconstitutional because it violated the Contract Clause of the United States Constitution. The Contract Clause states that no state shall pass any law impairing the obligation of contracts. The Supreme Court held that the tax was constitutional because it did not violate the Contract Clause. The Court reasoned that the tax was not a contract impairment because it did not alter the terms of the contract between the county and the railroad company. The Court also noted that the tax was not a taking of the railroad company's property without just compensation, as the tax was based on the value of the property and not on the amount of money the railroad company had invested in the property. The Court concluded that the tax was constitutional and that the county had the right to tax the railroad company for the value of its property. The Court also noted that the tax was not a taking of the railroad company's property without just compensation, as the tax was based on the value of the property and not on the amount of money the railroad company had invested in the property.

Justice Field delivered the dissenting opinion in Buena Vista County v. Iowa Falls & Sioux City Railroad Company, arguing that the majority's decision was an unjustified extension of state power over private property. He argued that while states have a right to tax public and quasi-public corporations, they do not have the authority to impose taxes on private companies for their own benefit without due process of law or just compensation. Furthermore, he contended that even if such taxation were permissible under certain circumstances, it would be unconstitutional for a state to levy taxes on one company but exempt similar businesses from taxation. In this case, Justice Field believed that by allowing Iowa to tax only one railroad company while exempting others from taxation violated both constitutional principles and fundamental fairness.