It was ratified by state legislatures.
1787
Delaware was the first state to approve the US Constitution.
not at first
September 17, 1787
The Missouri Constitution was approved in the year of 1945.
When the US Constitution was revised it would not be ratified (go into effect) unless 9 states approved it and accepted it.
The Missouri Constitution was approved in the year of 1945.
In late December of 1865 the twenty seven states approved of the thirteenth amendment to the US Constitution. This effectively outlawed slavery in the US.
Russia Constitution was approved on 12 of august in 1993.
Those were the states that voted on the first approved US Constitution.
The Constitution was ratified by the Constitutional Convention members in 1887.
The Articles of Confederation, the first form of central US government, were approved by the states in 1781, but proved too weak to be workable. The US Constitution replaced the Articles in 1787.