Article 4, Section 1
Elmendorf v. Taylor10 Wheat. 152 1825
Mr. Chief Justice Marshall. . . . Were this question now for the first time to be decided, a considerable contrariety [Volume 4, Page 479] of opinion respecting it would prevail in the court; but it will be unnecessary to discuss it, if the point shall appear to be settled in Kentucky. This court has uniformly professed its disposition, in cases depending on the laws of a particular state, to adopt the construction which the courts of the state have given to those laws. This course is founded on the principle, supposed to be universally recognised, that the judicial department of every government, where such department exists, is the appropriate organ for construing the legislative acts of that government. Thus, no court in the universe, which professed to be governed by principle, would, we presume, undertake to say, that the courts of Great Britain, or of France, or of any other nation, had misunderstood their own statutes, and therefore erect itself into a tribunal which should correct such misunderstanding. We receive the construction given by the courts of the nation, as the true sense of the law, and feel ourselves no more at liberty to depart from that construction, than to depart from the words of the statute. On this principle, the construction given by this court to the constitution and laws of the United States is received by all as the true construction; and on the same principle, the construction given by the courts of the several states to the legislative acts of those states, is received as true, unless they come in conflict with the constitution, laws or treaties of the United States. If, then, this question has been settled in Kentucky, we must suppose it to be rightly settled.
The Founders' Constitution
Volume 4, Article 4, Section 1, Document 11
The University of Chicago Press