Could the Convention propose a new Constitution and put it into effect through nine state conventions?

From these two acts, it appears, 1st, that the object of the convention was to establish, in these States, A FIRM NATIONAL GOVERNMENT; 2d, that this government was to be such as would be ADEQUATE TO THE EXIGENCIES OF GOVERNMENT and THE PRESERVATION OF THE UNION; 3d, that these purposes were to be effected by ALTERATIONS AND PROVISIONS IN THE ARTICLES OF CONFEDERATION, as it is expressed in the act of Congress, or by SUCH FURTHER PROVISIONS AS SHOULD APPEAR NECESSARY, as it stands in the recommendatory act from Annapolis; 4th, that the alterations and provisions were to be reported to Congress, and to the States, in order to be agreed to by the former and confirmed by the latter.

… They must have reflected, that in all great changes of established governments, forms ought to give way to substance; that a rigid adherence in such cases to the former, would render nominal and nugatory the transcendent and precious right of the people to "abolish or alter their governments as to them shall seem most likely to effect their safety and happiness,"(2) since it is impossible for the people spontaneously and universally to move in concert towards their object; and it is therefore essential that such changes be instituted by some INFORMAL AND UNAUTHORIZED PROPOSITIONS, made by some patriotic and respectable citizen or number of citizens. They must have recollected that it was by this irregular and assumed privilege of proposing to the people plans for their safety and happiness, that the States were first united against the danger with which they were threatened by their ancient government; that committees and congresses were formed for concentrating their efforts and defending their rights; and that CONVENTIONS were ELECTED in THE SEVERAL STATES for establishing the constitutions under which they are now governed; nor could it have been forgotten that no little ill-timed scruples, no zeal for adhering to ordinary forms, were anywhere seen, except in those who wished to indulge, under these masks, their secret enmity to the substance contended for. They must have borne in mind, that as the plan to be framed and proposed was to be submitted TO THE PEOPLE THEMSELVES, the disapprobation of this supreme authority would destroy it forever; its approbation blot out antecedent errors and irregularities. …

… For the sole and express purpose aforesaid a Convention of delegates is formed at Philadelphia: what have they done? Have they revised the confederation, and has Congress agreed to their report?—neither is the fact. This Convention have exceeded the authority given to them, and have transmitted to Congress a new political fabric, essentially and fundamentally distinct and different from it, in which the different states do not retain separately their sovereignty and independency, united by a confederate league—but one entire sovereignty, a consolidation of them into one government—in which new provisions and powers are not made and vested in Congress, but in an assembly, senate, and president, who are not known in the articles of confederation. Congress, without agreeing to, or approving of, this system proffered by the Convention, have sent it to the different legislatures, not for their confirmation, but to submit it to the people; not in conformity to their own resolution, but in conformity to the resolution of the Convention made and provided in that case.(53) Was it, then, from the face of the foregoing facts, the intention of Congress, and of this and the other states, that the essence of our present national government should be annihilated, or that it should be retained and only have an increase of substantial necessary powers? Congress, sensible of this latter principle, and that the Convention had taken on themselves a power which neither they nor the other states had a right to delegate to them, and that they could not agree to and approve of this consolidated system, nor the states confirm it—have been silent on its character; and although many have dwelt on their unanimity, it is no less than the unanimity of opinion that it originated in an assumption of power, which your voice alone can sanctify. …

Agreeably to the Articles of Confederation, entered into in the most solemn manner, and for the observance of which the states pledged themselves to each other, and called upon the Supreme Being as a witness and avenger between them, no alterations are to be made in those Articles, unless, after they are approved by Congress, they are agreed to, and ratified, by the legislature of every state; but by the resolve of the Convention, this Constitution is not to be ratified by the legislature of the respective states, but is to be submitted to conventions chosen by the people, and, if ratified by them, is to be binding.