Burley v. Flint 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 resident of the state of Michigan, who had received income from a business in the state of Ohio. The state of Michigan had imposed a tax on the income, and the plaintiff argued that the tax was unconstitutional. The Supreme Court held that the tax was unconstitutional, as it violated the Due Process Clause of the Fourteenth Amendment. The Court reasoned that the tax was an unreasonable burden on the plaintiff, as it was imposed on income that was earned in another state. The Court also noted that the tax was not necessary to protect the interests of the state of Michigan, as the income was not derived from any activity within the state. The Court concluded that the tax was an unconstitutional burden on the plaintiff, and that the state of Michigan could not impose a tax on the income of a non-resident. This decision established the principle that a state cannot impose a tax on income earned in another state, and it has been cited in numerous cases since.

Justice Field delivered the dissenting opinion in Burley v. Flint, arguing that the majority had incorrectly interpreted a provision of the California Constitution and failed to consider relevant case law from other states. He argued that under prior decisions by both state and federal courts, it was clear that an individual's right to contract could not be restricted unless there was a compelling public interest at stake. In this case, he argued, no such public interest existed; thus any restriction on Burley's ability to enter into contracts with whomever she chose violated her constitutional rights as well as those of Flint. Furthermore, Justice Field noted that even if some sort of restriction were necessary for the protection of society or individuals within it, such restrictions should only apply prospectively rather than retroactively - which would have been more consistent with established legal principles regarding contractual obligations. Ultimately then, Justice Field concluded his dissent by asserting that while he agreed with much of what had been said in the majority opinion about how contracts should be enforced between parties who are competent adults capable of making their own decisions without government interference - ultimately these considerations did not outweigh Burley's fundamental right to make her own contractual arrangements free from undue governmental regulation or interference