How many states were required to ratify the Constitution for it to take effect?

The correct answer is that 9 states were required to ratify the Constitution for it to take effect. This requirement was established in Article VII of the Constitution, which states that the Constitution would take effect once it was ratified by nine states. The framers chose this number as a compromise between the need for broad consensus among the states and the practicality of achieving ratification, especially since there were 13 states at the time.

While the other options present different numerical values, they do not accurately reflect the historical requirement for ratification. For instance, requiring all 13 states would have made it exceedingly difficult to implement the new government framework, given the varying interests and opinions among the states. The requirement of 2/3 of the states would apply to other legislative processes, such as amending the Constitution, but not to the original ratification of the document itself.