Ellis and Others v. Davis was a United States Supreme Court case that dealt with the issue of whether a state could tax the income of a non-resident. The case was brought by a group of non-residents who argued that the state of Tennessee had no right to tax their income, as they were not residents of the state. The Supreme Court ultimately ruled in favor of the non-residents, holding that a state cannot tax the income of a non-resident. The Court reasoned that the power to tax is an attribute of sovereignty, and that a state cannot exercise its power of taxation beyond its own borders. The Court further held that the power to tax is limited to the territory of the state, and that a state cannot tax the income of a non-resident. This decision has been cited in numerous cases since, and has been used to support the principle that a state cannot tax the income of a non-resident.

Justice Field delivered the dissenting opinion in Ellis and Others v. Davis, arguing that the majority's decision was wrongfully based on a misapplication of existing law. He argued that under the terms of an 1845 contract between two parties, one party had agreed to pay for certain improvements made by another party to a piece of property they jointly owned. The majority held that this agreement was invalid because it did not comply with state statutes requiring such contracts be in writing; however, Justice Field disagreed with this interpretation and instead argued that these requirements only applied when both parties were attempting to convey title or interest in land - which was not applicable here as no transfer of title or interest occurred. Furthermore, he noted there existed ample evidence proving both parties' intent to enter into an enforceable agreement regarding payment for said improvements despite its lack of written formality. Thus, he concluded his dissent by stating the court should have enforced the contract as it stood rather than relying on technicalities which would ultimately lead to unjust results for all involved