Whilst the General Assembly thus declares the rights retained by the States, rights which they have never yielded, and which this State will never voluntarily yield, they do not mean to raise the banner of disaffection, or of separation from their sister States, co-parties with themselves to this [constitutional] compact. They know and value too highly the blessings of their Union as to foreign nations and questions arising among themselves, to consider every infraction as to be met by actual resistance. They respect too affectionately the opinions of those possessing the same rights under the same instrument, to make every difference of construction a ground of immediate rupture. They would, indeed, consider such a rupture as among the greatest calamities which could befall them; but not the greatest. There is yet one greater, submission to a [federal] government of unlimited powers...
Thomas Jefferson, Declaration and Protest, on the Principles of the Constitution of the United States of America, and on the Violations of Them, 1825
( https://avalon.law.yale.edu/19th_century/jeffdec1.asp )
Mr. Jefferson clearly considered secession to be a right retained by the States. That may be worth remembering today, as Americans are increasingly expected to submit, without recourse, to a federal government of essentially unlimited powers...
The right of secession was written into the Virginia Ratification document:
"WE the Delegates of the people of Virginia, duly elected in pursuance of a recommendation from the General Assembly, and now met in Convention, having fully and freely investigated and discussed the proceedings of the Federal Convention, and being prepared as well as the most mature deliberation hath enabled us, to decide thereon, DO in the name and in behalf of the people of Virginia, declare and make known that the powers granted under the Constitution, being derived from the people of the United States may be resumed by them whensoever the same shall be perverted to their injury or oppression, and that every power not granted thereby remains with them and at their will: that therefore no right of any denomination, can be cancelled, abridged, restrained or modified, by the Congress, by the Senate or House of Representatives acting in any capacity, by the President or any department or officer of the United States, except in those instances in which power is given by the Constitution for those purposes: and that among other essential rights, the liberty of conscience and of the press cannot be cancelled, abridged, restrained or modified by any authority of the United States." ["Virginia's Ratification Convention." June 26, 1788]
Two other states also specifically reserved the right of secession.
"That the Powers of Government may be reassumed by the People, whensoever it shall become necessary to their Happiness; that every Power, Jurisdiction and right, which is not by the said Constitution clearly delegated to the Congress of the United States, or the departments of the Government thereof, remains to the People of the several States, or to their respective State Governments to whom they may have granted the same; And that those Clauses in the said Constitution, which declare, that Congress shall not have or exercise certain Powers, do not imply that Congress is entitled to any Powers not given by the said Constitution; but such Clauses are to be construed either as exceptions to certain specified Powers, or as inserted merely for greater Caution." ["New York Ratification Convention." July 26, 1788]
"That the powers of government may be reassumed by the people, whensoever it shall become necessary to their happiness:- That the rights of the States respectively, to nominate and appoint all State Officers, and every other power, jurisdiction and right, which is not by the said constitution clearly delegated to the Congress of the United States or to the departments of government thereof, remain to the people of the several states, or their respective State Governments to whom they may have granted the same; and that those clauses in the said constitution which declare that Congress shall not have or exercise certain powers, do not imply, that Congress is entitled to any powers not given by the said constitution, but such clauses are to be construed as exceptions to certain specified powers, or as inserted merely for greater caution." ["Rhode Island Ratification Convention." May 29, 1790]
The acceptance of those states into the Union enshrined the right of secession into the Constitution as a Supreme Law of the Land.
Mr. Kalamata