Who Are the Parties to the Constitutional Contract?

A recent post by Tom W. Bell of Agoraphilia and two recent posts by Timothy Sandefur of Positive Liberty sent me back to The Federalist Papers, specifically, to No. 39 by James Madison. There, Madison says that

the Constitution is to be founded on the assent and ratification of the people of America, given by deputies elected for the special purpose; but, on the other, that this assent and ratification is to be given by the people, not as individuals composing one entire nation, but as composing the distinct and independent States to which they respectively belong. It is to be the assent and ratification of the several States, derived from the supreme authority in each State, the authority of the people themselves. The act, therefore, establishing the Constitution, will not be a NATIONAL, but a FEDERAL act.
That it will be a federal and not a national act, as these terms are understood by the objectors; the act of the people, as forming so many independent States, not as forming one aggregate nation, is obvious from this single consideration, that it is to result neither from the decision of a MAJORITY of the people of the Union, nor from that of a MAJORITY of the States. It must result from the UNANIMOUS assent of the several States that are parties to it, differing no otherwise from their ordinary assent than in its being expressed, not by the legislative authority, but by that of the people themselves. Were the people regarded in this transaction as forming one nation, the will of the majority of the whole people of the United States would bind the minority, in the same manner as the majority in each State must bind the minority; and the will of the majority must be determined either by a comparison of the individual votes, or by considering the will of the majority of the States as evidence of the will of a majority of the people of the United States. Neither of these rules have been adopted. Each State, in ratifying the Constitution, is considered as a sovereign body, independent of all others, and only to be bound by its own voluntary act. In this relation, then, the new Constitution will, if established, be a FEDERAL, and not a NATIONAL constitution. . . .
[T]he proposed government cannot be deemed a NATIONAL one; since its jurisdiction extends to certain enumerated objects only, and leaves to the several States a residuary and inviolable sovereignty over all other objects.

The persons who signed the Constitution in 1787 signed it as representatives of the people of their respective States. The persons who then ratified the Constitution in special conventions did so as representatives of the people of their respective States. The Constitution is a contract among the States on behalf of the people of each State. The States retain sovereignty, on behalf of their people, except where the Constitution transfers it to the United States (e.g., the regulation of interstate commerce).

See "The Constitution: Myths and Realities".