Mowry v. Whitney was a United States Supreme Court case that dealt with the issue of whether a state could constitutionally require a person to pay a tax on the transfer of real estate. The case was brought by the plaintiff, William Mowry, who was a resident of Rhode Island. Mowry had purchased a piece of real estate in the state and was required to pay a tax on the transfer of the property. Mowry argued that the tax was unconstitutional because it violated the Fourteenth Amendment's Equal Protection Clause. The Supreme Court held that the tax was constitutional. The Court reasoned that the tax was a valid exercise of the state's police power and that it did not violate the Equal Protection Clause. The Court noted that the tax was applied uniformly to all transfers of real estate and that it was not discriminatory in any way. The Court also noted that the tax was not excessive and that it was necessary to raise revenue for the state. In conclusion, the Supreme Court held that the tax was constitutional and that it did not violate the Equal Protection Clause of the Fourteenth Amendment. The Court noted that the tax was applied uniformly and that it was necessary to raise revenue for the state.

In Mowry v. Whitney, the Supreme Court was asked to decide whether a state law that allowed for the sale of mortgaged property without notice to the debtor violated due process rights under the Fourteenth Amendment. The majority opinion held that such laws did not violate due process because they were in place before adoption of the amendment and had been accepted by society as valid since then. However, Justice Field dissented from this view, arguing that although states have traditionally regulated mortgages through their own laws, these regulations should be subject to constitutional scrutiny when challenged on grounds of violating fundamental rights protected by federal law. He argued further that while it may be true that some states allow for sales without notice or hearing prior to foreclosure proceedings, this does not mean all such statutes are necessarily valid; rather each must be evaluated based on its own merits and judged against applicable constitutional standards.