Question

Whose presence was considered “a must” in order to get a national convention to create a new government

Answer 1

I believe the answer is: Congress/legislators

In order to create a new government, a society need to establish a body that had the authorization to create regulation that must be followed by its people. Because of this, the existence of congress (which filled with all delegates from states) are necessary so each states could be represented during the law making process.