The first time we used state ratifying conventions was to ratify the Constitution itself. Hamilton and Madison wanted it understood that the Articles of Confederation and the Constitution were two different legal concepts. The Articles were a treaty between sovereign powers, governed under treaty law. The Constitution was a compact, or contract, between the Whole People and the federal government they created. The states were the agents of the Whole People, not the actual parties to the contract. As such, the Constitution was governed under contract law, not treaty law.
To help make this clearer, I'll provide you with two links to Publius Essays I wrote for the purpose of FReeper education.
Federalism: Yesterday and Today is a 10,000 word essay on the history of federalism from the Founding through the present.
Because I slighted the present era, I wrote a short sequel, Reflections on the 82nd Anniversary of the New Deal, that delved into the New Deal-to-the-present period. Some day, I'll merge the two essays.
The Articles had never been presented to the people for a vote, and Madison and Hamilton wanted a vote of the people to emphasize the contract nature of the Constitution. The Federalist Papers were written by Madison, Hamilton and Jay to convince New York's ratifying convention to ratify the document.
The decision to use state ratifying conventions to ratify the 21st Amendment came from a completely different problem.
The bootlegging industry had its tentacles deeply embedded into both government and law enforcement at the local, county, state and federal levels. Congress feared that if the ratification of the 21st Amendment were left to the state legislatures, the congressional seven year window for ratification would expire and repeal would die. While the people overwhelmingly wanted repeal, law enforcement and government wanted Prohibition to remain for its ability to provide bribes and payoffs. This is why Congress chose the state ratifying convention method.
The states decided how ratifying conventions would be elected by the voters, and these conventions met, debated, voted to ratify or not to ratify, and then adjourned. It took a mere nine months for the 21st to be ratified by this method.
State ratifying conventions and a Convention of the States are two completely different things.
I still have not mastered this distinction, Publius. I suspect I am not alone in this.
So I will now go and study the links that you and xzins have so kindly provided.
Thank you so very much for writing!