In 1775, there were no State Constitutions in America, whatsoever. At that time and place, each of what ended up becoming a State, were all legally still colonies of Great Britain, with a charter by Great Britain so having been provided to each one of those colonies. However, as those colonies united in a common cause which thereby became known as the American War of Independence, it became common sense that each one of those colonies, would proclaim themselves instead as an individual State, under the aegis thereof of a State Constitution which thereby made them sovereign to that State, and no longer colonial subjects to Great Britain. It was those State Constitutions, that in many respects, formed the necessary foundation for the subsequent Constitution of these United States. Of course, without a successful revolution, those State Constitutions would thereby have become null and void.
Governments, don’t just happen overnight; but rather they have to have some sort of prevailing document, that serves the purpose of thereby creating that government which in sound principle has a legislative branch, an executive branch and a judicial branch; each with its particular form and function, so needed in order to conduct good governance. Further to the point, legitimate governments, are answerable to the people; of which, the personages so representing the people should be elected by the people or be appointed by upstanding members of that community, and each of those representatives needs to be held accountable to those people. Additionally, another important reason why State Constitutions were so created and written, besides to break free from Great Britain, and besides the need to outline the point and purpose of that government, was for that Constitution to also make their case to the people, at large; so that the people would therefore see the advantages of this new form of government, over that previous government, so enforced upon them, without the people’s fair representation, which therefore signified that previous government’s failure to value the people and their unalienable rights.
So too, those State Constitutions sent a very loud and clear signal to Great Britain, that those that were previously colonists to that empire, were no longer subservient to that domain. This meant that those that were “sitting on the fence,” so to speak, would have to make a conscious choice as to which side that they were now on; and those that did not countenance revolution with Great Britain, perhaps because of the benefits that they were receiving by working in conjunction with such, would themselves by that loyalty, had made their choice, with consequences, so of. For a certainty, Great Britain, was aware that they had a “problem” in America, and while there was still a fair amount of influential people, on both sides, that thought that there might be some sort of accommodation that could satisfy, both parties, the reality was, that the die had been cast, and that therefore there could only be one winner. So, Great Britain put together a fearsome naval force, to take back what they felt was theirs to take, and in their failure of that objective, those thirteen States became united, so known today, as the United States of America.