I see people arguing all the time over when, exactly, "the American experiment" ended. It seems to be on many people's minds, especially with the recent 250th commemoration of the Declaration of Independence ("Independence Day").
I think most of them believe it lasted much longer than it did.
The American experiment lasted only from the signing of the Declaration of Independence until the ratification of the Constitution. That was the end of that.Shays' Rebellion was a clear sign that the founders had made a critical mistake by creating a government, but once they established an actual State with the Constitution, it was done. The experiment had failed, and everything since then hasn't been "American", but something less; a cheaper version designated by the letters "USA".