What event brought about the end of organized opposition to the constitution?

Answer 1

I don't know that there was any one single event which can be given the credit for ending organized opposition to the U.S. Constitution, but there were two events that were key to its adoption. First, there was the now-infamous "3/5 compromise" in Article I, whereby slaves were to be counted as 3/5 of a person for purposes of congressional apportionment. Much misunderstood today as a statement of racism, this clause in Article I was the North's idea. The South was demanding that slaves be counted for purposes of congressional apportionment, but the North said, no, can't do that, you can't own slaves that you don't treat as people yet have them counted as people when it comes time to award congressional seats based on the number of people. In short, the North said that "you can't have it both ways". Rather than have the constitutional effort collapse altogether, the 3/5 compromise was offered by the North, to which the South agreed. This helped bring the nation together in 1787...but only for the next "fourscore and seven years", when the issue would be settled once-and-for-all by the Civil War.

The other seminal event in obtaining ratification of the Constitution by the original thirteen states, was the promise of the inclusion of a "Bill of Rights", which was a slate of twelve amendments to the Constitution, of which ten were actually adopted in the final document.