They declared their independence from Britain in 1776. Acting as independent, sovereign States they drafted and ratified the Articles of Confederation in 1781. They did not "pass into the Union" until the ratification of the Constitution in 1789. You may follow Abraham Lincoln's logic if you wish, but history records a different reality.
Sure, you can say that, but we are talking about fine points of word definitions.
Lincoln implied, and I agree, that "the Union" began with the First Continental Congress in 1774.
This Union, not individual states, then declared the colonies to be "free and independent states", but states of the Union itself.
And all states remained within the Union throughout the periods of Contenental Congresses, Articles of Confederation and the new Constitution.
The Articles themselves were first drawn up by the same Continental Congress, and at the same time, mid-1776, as the Declaration of Independence.
So the Articles were in effect and operating from Day One of Independence, and ratified by all but Maryland within a year of submission.
Indeed, the very name of the Articles is:
Point is: as Lincoln said, no state existed before the Union declared it independent, and no original state existed outside the Union before the new Constitution was ratified.
So, as to which came first, the chicken or the egg, I agree the Union created the states.