Those 13 colonies were not nation-states
Yes, they were declared to be free, sovereign and independent states by the Declaration of Independence:
We, therefore, the representatives of the United States of America, solemnly publish and declare, That these United Colonies are, and of right ought to be, FREE AND INDEPENDENT STATES; that they are absolved from all allegiance to the British crown and that all political connection between them and the state of Great Britain is, and ought to be, totally dissolved; and that, as free and independent states, they have full power to levy war, conclude peace, contract alliances, establish commerce, and do all other acts and things which independent states may of right do.
This was discerned from what the Law of Nations defined in Book I, Chapter I, §11: “Of a state that has passed under the dominion of another:”
But a people that has passed under the dominion of another is no longer a state, and can no longer avail itself directly of the law of nations. Such were the nations and kingdoms which the Romans rendered subject to their empire; the generality even of those whom they honoured with the name of friends and allies no longer formed real states
. Within themselves, they were governed by their own laws and magistrates; but without, they were in every thing obliged to follow the orders of Rome; they dared not of themselves either
to make war or contract alliances; and could not
treat with nations.
Meanwhile The Declaration of Independence was
framed in the language of the "Law of Nations," to justify the American colonies' separation from Great Britain to the world, and to gain international recognition and support. It argued that the colonies had the right, under the law of nature and of nature's God, to separate and form their own independent states. This established the new United States as independent actors with the power to engage in diplomacy, war, and commerce, just like any other sovereign nations.
Therefore since the states
could “make war, contract alliances, and treat with other nations," and “do all
other acts and things which independent states may of right do;” the states were
not under the dominion of another, and thus were 13 separate sovereign nations.
And this was in the following
context from the Law of Nations, §10. “Of states forming a federal republic:”
Finally, several sovereign and independent states may unite themselves together by a perpetual confederacy, without ceasing to be, each individually, a perfect state. They will together constitute a federal republic: their joint deliberations will not impair the sovereignty of each member, though they may, in certain respects, put some restraint on the exercise of it, in virtue of voluntary engagements. A person does not cease to be free and independent, when he is obliged to fulfill engagements which he has voluntarily contracted.
As such, the states simply formed an international union of (thirteen) separate sovereign nations— just like the United Nations or the European Union, after them; and each nation simply delegated powers to the United States as such a federal republic, being a “voluntary engagement among a perpetual confederacy” among separate sovereign nations, whose joint deliberations did not impair the sovereignty of each nation.
Meanwhile Lincoln re-wrote history to claim that the Declaration of Independence established a national union in 1776, that was political superior to the states:
July 4th Message to Congress:
Having never been States, either in substance or in name, outside of the Union, whence this magical omnipotence of "State rights," asserting a claim of power to lawfully destroy the Union itself?
Much is said about the "sovereignty" of the States, but the word even is not in the National Constitution, nor, as is believed, in any of the State constitutions. What is a "sovereignty" in the political sense of the term? Would it be far wrong to define it "a political community without a political superior"? Tested by this, no one of our States, except Texas, ever was a sovereignty; and even Texas gave up the character on coming into the Union, by which act she acknowledged the Constitution of the United States and the laws and treaties of the United States made in pursuance of the Constitution to be for her the supreme law of the land.
... y the Declaration of Independence... the 'United Colonies' were declared to be 'free and independent States;' but even then the object plainly was not to declare their independence of one another or of the Union, but directly the contrary...."
The States have their status in the Union, and they have no other legal status. If they break from this, they can only do so against law and by revolution.
So Lincoln falsely claimed that the Declaration of Independence declared a national union that political superior to the states-- and on that basis, he waged total war on non-complying states --by turning the majority-states against them, through totalitarian suppression of the truth.
And accordingly, the people will NEVER consent to their government as equals.