Of course the Union was preexisting. That was the purpose of the Articles of Confederation. That was the purpose of the Declaration of Independence, which declared the independence of each state simultaneously with pledging to each other their lives, fortunes and sacred honor.
Was Adams the ambassador of Massachusetts? No? Of what was he ambassador?
George Washington was by appointment of the Continental Congress as General of the army of what state?
The flag with the stripes and stars, carried over the Continental Army, what state was that the flag of?
Of course the Union existed prior to the constitution.
Of course Jackson’s proclamation doesn’t prove he believed it, because he might have falsely issued a proclamation. Just as some nominally educated people pretend to not know that the Union preexisted the Constitution, the Articles of Confederation, and the Declaration of Independence.
“Of course the Union existed prior to the constitution.”
That has not been in dispute. The Articles of Confederation, created by the colonies/states, preceded the Constitution. And the Articles state:
“Each state retains its sovereignty, freedom, and independence, and every power, jurisdiction, and right, which is not by this Confederation expressly delegated to the United States, in Congress assembled”
‘Each state retains its sovereignty, etc..’
Of course Lincoln, ever the lawyer, argued that the Union began with the Articles of Association in 1774; what actually began in 1774 was the Continental Congress, and those Articles of Association began by stating “We, his majesty’s most loyal subjects,...”
http://avalon.law.yale.edu/18th_century/contcong_10-20-74.asp
Doesn’t exactly sound like an independent Union, despite Lincoln’s attempt to make it so; it was the beginning of the Continental Congress, but that Congress was created by the colonies/states; they existed before it did; how the Union they created pre-existed them is something only Lincoln and his acolytes can know.