Three years later Mr. Douglas carefully set forth his doctrine again in the Kansas-Nebraska Bill itself. Referring to the Missouri Compromise, with its prohibition of slavery in the states to be erected out of Louisiana territory north of 36° 30´, the bill said:
Which being inconsistent with the principle of non-intervention by Congress with slavery in the states and territories, as recognized by the legislation of 1850 ... is hereby declared inoperative and void; it being the true intent and meaning of this act not to legislate slavery into any territory or state, nor to exclude it therefrom, but to leave the people thereof perfectly free to form and regulate their domestic institutions in their own way, subject only to the Constitution of the United States.
Mr. Douglas's doctrine, popularly known as "Squatter Sovereignty," was open to criticism on very obvious constitutional and historical grounds.
The original conception of the Union had undoubtedly been that it was a confederacy of states, each sovereign within itself except in so far as it had surrendered to the National Government a part of its sovereignty by accepting the Federal Constitution and entering the Union. It was deemed an axiom that each state was free by the will of its own citizens to regulate its domestic affairs in its own way, permitting or forbidding slavery at its own free will. After the great slavery controversy arose the South contended still for this doctrine of states' rights, and by the Kansas-Nebraska Bill, this sovereignty of the states was extended to the territories also.
The student of history must observe however that that doctrine had been very greatly impaired if not indeed set aside by the act of Virginia in ceding her claims in the Northwest Territory and the acceptance of that cession by the general government. In that cession it had been stipulated that slavery should never be permitted in any of the territory thus made a part of the national domain. The cession was made with the direct intent that the region concerned should presently be divided and admitted into the Union as a number of states. But those states were thus forbidden in advance to permit the existence of slavery within their borders. So far as they were concerned, therefore, the supposed right of a state to legislate at will on that subject was taken away from them even before their birth.
Here it would seem there was an abrogation or at least an important modification of the doctrine of the right of each state to determine this question for itself, and that modification had been made by Virginia and everywhere accepted.
The Missouri Compromise in precisely the same manner had taken away that right of determination from all the states that might be formed out of the Louisiana territory lying north of the southern line of Missouri. If the prohibition thus laid upon yet unborn states was permissible as regards the cession of the Northwest Territory it would seem to have been equally so with regard to the new domain west of the Mississippi.
Further than this the sovereign right of a state to determine this question for itself did not extend at any time to the territories. Under the Constitution as uniformly interpreted by the Supreme Court of the United States, Congress is supreme in the territories and may make any law that it pleases for their governance. In other words the people of the territories have absolutely no rights of self-government except such as Congress may from time to time see fit to confer upon them.
This statement is not made speculatively or as an opinion of the historian. It is a well settled doctrine of constitutional law, affirmed by every court to which the question has at any time been submitted.
Senator Douglas's Kansas-Nebraska Bill was based upon an assumption precisely the reverse of this. It extended to the territories a sovereignty which under the Constitution belonged only to states, and which, as has been suggested, the states themselves had in a large degree surrendered by the acceptance of the cession of the Northwest Territory.