A clause was added to the US Constitution that set the minimum number of states required to ratify the Constitution. A minimum of states had to ratify the US Constitution for it to go into effect.

A minimum of 9 states had to ratify the US Constitution for it to go into effect.

Explanation:

On September 28, Congress directed the state legislatures to call ratification conventions in each state. Article VII stipulated that nine states had to ratify the Constitution for it to go into effect

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