Today marks the 229th anniversary . . .
. . . of the surrender of Cornwallis at Yorktown, Maryland, October 19th 1781. Did the War of Independence end that day? No, but the outcome was assured. Here is a good summary (from Wikipedia):
In London, as political support for the war plummeted after Yorktown, Prime Minister Lord North resigned in March 1782. In April 1782, the Commons voted to end the war in America. Preliminary peace articles were signed in Paris at the end of November, 1782; the formal end of the war did not occur until the Treaty of Paris and Treaties of Versailles were signed on September 3, 1783. The last British troops left New York City on November 25, 1783, and the United States Congress of the Confederation ratified the Paris treaty on January 14, 1784.
The British decision to surrender came very quickly, only a few weeks after the news got back to Europe. Because they actively fought alongside the Americans, the French and their allies were involved in the negotiations.
Did you notice the Treaty of Paris was ratified by the United States Congress of Confederation? It was clear as much as five years earlier the government was too weak to function. A stronger government must be established. It is right to celebrate on this day the achievement of independence in fact. It is also essential to notice the Americans who fought for more than six years were never fighting for each State or Commonwealth to “go it alone.” Look again:
We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.
It is clear, “We the People of the United States . . . do ordain and establish this Constitution for the United States of America.” Do not buy a book promoting the idea that there is somehow a right of secession. Our fathers, who wrote and ratified the Constitution, never had in mind that States could go their own way.
You say you heard that Jefferson himself was quoted (some twenty years later) saying if people want to leave, it is fine with him. I can actually find the Jefferson quote, but the source is always suspect. Jefferson is actually the forefather who, as President acted boldly to realize his vision of a great continental country. He is also the first President to project American power. Jefferson took us to war in the Mediterranean against the Barbary states (Islamist jihad, you know) in 1805. We won.