How many states had to agree to the law for it to be enacted?

Article VII stipulated that nine states had to ratify the Constitution for it to go into effect. Beyond the legal requirements for ratification, the state conventions fulfilled other purposes. The Constitution had been produced in strictest secrecy during the Philadelphia convention.

Article Seven of the US constitution deals with the number of state ratification required for the constitution to take effect and the method for the states to ratify it. As per the article seven of the constitution, ratification conventions were organized in thirteen states and the ratification of nine states was required for the constitution to take effect. Delaware was the first state to ratify the constitution, New Hampshire was ninth and Rhode Island was the last state to ratify it as per the article seventh of Constitution.