[BroJoeK]

DiogenesLamp: "It [secession] was so very *NOT* illegal, that New York, Virginia, and Rhode Island all claimed a right to secede in their own ratification statements.
None of the framers said "You can't do that. It's illegal."
They all simply accepted those state's ratifications and did not see a conflict."

Every Founders' expression of a "right to secede" was couched within the term "necessary" or, as Virginians said, powers "may be resumed by them whensoever the same shall be perverted to their injury or oppression...".

"Injury or oppression" as spelled out in, for example, our 1776 Declaration of Independence.
No Founder ever proposed or supported an unlimited "right of secession" at pleasure.

[DiogenesLamp]

Every Founders' expression of a "right to secede" was couched within the term "necessary"...

Their collective expression as written in the Declaration of Independence says nothing of necessity. It says that it's up to the people for whatever reason they wish.

or, as Virginians said, powers "may be resumed by them whensoever the same shall be perverted to their injury or oppression...".

And who gets to decide whether or not they were "injured"? The people "injured", or the people doing the "injuring"?

Clearly Virginia thought they were injured in April of 1861 when Lincoln called for troops to attack the Southern states.

"Injury" is in the eye of the beholder.