"Happy for us that when we find our constitutions defective and insufficient to secure the happiness of our people, we can assemble with all the coolness of philosophers and set it to rights, while every other nation on earth must have recourse to arms to amend or to restore their constitutions." --Thomas Jefferson
A Constitutional Conference or an Amendment?
Madison specified the procedure outlined in Article V that says amendments can originate from one of two sources.
First, they can be proposed by Congress. Then, they must be approved by a two-thirds majority in both the House and the Senate before being sent to the legislatures in all the states. If three-quarters of state legislatures vote to approve an amendment, it becomes part of the Constitution.
A second method allows for the petitioning of Congress by the states: Upon receiving such petitions from two-thirds of the states, Congress must call a convention for the purpose of proposing amendments, which would then be forwarded to the states for ratification by the required three-quarters.
All the current Constitutional amendments were created using the first method.