On April 23, 1787, the Confederation Congress extended the post office franking privilege to all commissioners about to attend the Constitutional Convention. In other words, Congress gave to convention delegates the same privilege to send and receive free mail its own members enjoyed.
Why is that important? Because it tends to show that Congress accepted that the convention might do more than merely propose amendments to the Articles of Confederation.
As I’ve documented here and here, in September 1786 the Annapolis Convention recommended that the states gather the following May in Philadelphia. Two months later New Jersey became the first state to appoint commissioners to the Philadelphia conclave. On December 1, 1786 Virginia issued the formal convention call. By late February, 1787, seven states had agreed to participate. Each granted its commissioners power to go beyond amending the Articles.
On February 21, Congress, having rejected two motions to “recommend” courses of action, expressed its non-binding “opinion” that the convention be limited to amending the Articles. Many writers have confused this resolution with a convention call. But Virginia had issued the call nearly three months earlier, and the wording of the congressional resolution was not worded like a call.
It is understandable that Congress would prefer a convention that merely proposed amendments to the Articles. After all, a broader reform might put Congress itself out of business. But by April 23 it was abundantly clear that Congress was not going to get its way. Not one of the seven states agreeing to participate before February 21 had narrowed the scope of their commissions. In fact, they had been joined by South Carolina, which also granted its delegates broad powers. (Connecticut and Maryland were to do the same later). Only New York and Massachusetts had subscribed to the congressional “opinion.”
So what was Congress’s response? As a rule, politicians do not reward people who go in a direction those politicians do not approve. Yet on April 23, Congress decided to facilitate the convention with the grant of free postage. At a time when postage was, relatively speaking, far more expensive than it is today, this was a very significant subsidy.
In other words, Congress was willing to support a convention with broad powers after all. No wonder that on September 28, 1787 Congress voted unanimously to transmit the finished Constitution to the states for ratification.
The resolution granting postal franking to all convention commissioners can be found in the Journals of the Continental Congress, volume 32, p. 228.