North v. McDonald was a United States Supreme Court case that dealt with the issue of whether a state could impose a tax on a non-resident's income. The case was brought by a resident of the state of New York, who had been assessed a tax on his income from a business in the state of Massachusetts. The plaintiff argued that the tax was unconstitutional, as it violated the Due Process Clause of the Fourteenth Amendment. The Supreme Court held that the tax was constitutional, as it was a valid exercise of the state's power to tax. The Court noted that the tax was not discriminatory, as it applied equally to all non-residents, regardless of their state of residence. Furthermore, the Court held that the tax was not an undue burden on interstate commerce, as it was not excessive or oppressive. In conclusion, the Supreme Court held that the tax was constitutional, as it was a valid exercise of the state's power to tax. The Court noted that the tax was not discriminatory, and did not impose an undue burden on interstate commerce.

Justice Field delivered the dissenting opinion in North v. McDonald, arguing that the majority's decision was contrary to both precedent and common sense. He argued that a contract between two parties should be enforced according to its terms, regardless of any subsequent changes in law or circumstances which may have occurred since it was made. In this case, he noted that there had been no change in either the law or the facts since McDonald entered into his agreement with North; thus, Field believed that McDonald should not be relieved from his contractual obligations simply because they were now more burdensome than when he originally agreed to them. Furthermore, Justice Field asserted that if such relief were granted here then similar contracts could be voided whenever their performance became difficult due to unforeseen events - an outcome which would lead to chaos and uncertainty for all involved parties.