How many states had to vote for the constitution to approve it

According to Article Seven of the Constitution of the United States, nine states had to vote for the Constitution to approve it.

Explanation:

The ratification of the Convention of the nine States could be sufficient for the establishment of the Constitution among the States that ratified it. But this process posed a problem and a danger to the Constitution of the United States: if it was not ratified by all States (the original thirteen), states that rejected ratification could be divided into different countries. Thus, when New Hampshire became the ninth state to ratify it (1788), Virginia, New York, North Carolina and Rhode Island waited to see which of the two options (whether to ratify Article VII or give rise to other countries) was more popular and more beneficial for the US. The Congress, established under the Articles of the Constitution, elected on March 4, 1789 as the day "to begin the constitutional process." Virginia and New York ratified the Constitution before this date; North Carolina and Rhode Island ratified it later. Then the new rulers took power in the remaining eleven states.

la segunda guerra mundial comenzó el 1 de septiembre de 1939 y terminó el 2 de septiembre de 1945. ¡espero que esto ayude!