The DOI wasn’t a “founding document” in as much that it only created a separation from England and established sovereignty. It didn’t truly found our nation. The Constitution did that.
I said it was A founding document, not THE founding document.
Without the Declaration, the Virginia Declaration of Rights, and the Articles of Confederation, there would have been no Constitution. These are all founding documents.
The Declaration provides the “why”.
The Constitution provides the “how”.