And the Continental Congress was formed at the behest of the individual colonies, so there.
So long as we date the independence of the whole to July 4, 1776 - and I believe you'll find it rather difficult convince much of anyone otherwise - the irrefutable reality of the timeline indicates that individual state independence from Britain had already been declared in multiple cases over the previous month. Virginia ceased to be a colony and became a Commonwealth, or State, in June of 1776. Acting as representatives of that new Commonwealth, her delegates subsequently voted in favor of independence for the whole of the colonies and states in July.
Using your thinking regarding independence it had been declared prior to 1776 by the actions of the colonies which included forming the Continental Army in June of 1775. July 4 was just the official declaration coming years after the first actions pointing to independence and months after the first acts of armed rebellion and over a year after the founding of the Continental Army.
Colonial legislatures brought a national consciousness to bear and formed a Nation prior to 7/4/76. That consciousness predated states and produced such declarations as the "Declaration of Causes and Necessity of Taking Up Arms" and later directed the states to write constitutions. They all realized that only by uniting could they hope to suceed in defying Great Britain.