[MamaTexan]

Did the States have their fingers crossed when they signed documents creating a binding, perpetual union?

A cute but ineffectual remark.

The Constitution was a voluntary contract with NO provision for future coercion.

By law, any contract voluntarily entered can also be voluntarily exited upon legal notice.

That's what this means:

Amendment X
Powers of the States and People. Ratified 12/15/1791.
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people

[Luis Gonzalez]

"The Constitution was a voluntary contract with NO provision for future coercion."

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.

Posterity posterity n. 1. Future generations. 2. All of a person's descendents. (Lat. posteritas.) Source: AHD

Ordain ordain v. 2. To order by or as if by decree. (Lat. ordinaire, to organize) Source: AHD

[Non-Sequitur]

By law, any contract voluntarily entered can also be voluntarily exited upon legal notice.

But with the exception of the first 13, states didn't voluntarily enter into anything. They were admitted, and only with the permission of a majority of the other states as expressed by a vote in both houses of Congress. So if the approval of the other states is needed to become a state in the first place then why isn't the approval of the other states needed to leave?