Hear, Hear, Publius!
To those who insist on dragging out that tired old saw, it should be sufficient to note that what emerged from that assembly was an AMENDMENT to the existing Articles of the Confederation which was submitted to Congress, which in turn unanimously approved said amendment and referred it to the 13 states for ratification.
Now, before anything else occurred, it's important to note that the ratification process set forth in the amendment, which was, in fact, the soon-to-be new Constitution, contained two important changes which were both required for ratification to occur.
First, rather than have 13 state legislatures approve the amendment, as required under the Articles, the Constitution called for each state merely to approve the calling of a state convention to ratify the amendment. If that were approved, then the ratification of only nine states was deemed sufficient.
The fact is that ALL 13 states legislatures approved the calling of state conventions to consider approval of the new amendment / Constitution, and in so doing, the requisite unanimous approval for the new nine-state ratification process occurred.
Eventually, all thirteen states adopted the Constitution, thus further negating any claim that the Constitution was somehow illegally approved.
It's a matter of history*.
Source: David F. Guldenschuh, JD