Let the people of New England pluck the pine logs from their own eyes before talking of hickory splinters in the eyes of the South.
And then Douglas took up the history of the formation of the Union.

What went into the Union?
Sovereign states.

Who concluded a treaty of peace with Great Britain after the Revolution?
The thirteen sovereign states that had waged the war.

Who formed themselves into the Confederate States, each retaining its sovereignty?
The same states.

Who left that union and formed the present Union?
The same states.