BJK, read the text below and see if you can identify the words that do not belong:
“That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, - That whenever any Form of Government become destructive of these ends, it is the Right of the People to alter or to abolish it, provided it is really, really, REALLY necessary, - and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness, provided it is done with the mutual consent of all parties.”
What doesn't belong is your claim that our Founders ever favored disunion or secession "at pleasure", meaning absent either mutual consent or necessity caused by oppression & usurpations.
Remember their examples: 1) the Declaration of Independence included a long list of serious grievances against the British king, and those made independence necessary.
2) Replacing the old Articles of Confederation was done by mutual consent.
Again I say, if you care to learn what our Founders really believed on this subject, start with James Madison.