But Lee did not.
"The framers of our Constitution never exhausted so much labor, wisdom and forebearance in its formation, and surrounded it with so many guards and securities, if it was to be broken by every member of the Confederacy at will. It was intended for 'perpetual union' so expressed in the preamble, and for the establishment of a government, not a compact, which can only be dissolved by revolution, or the consent of all the people in convention assembled. It is idle to talk of secession." January 23, 1861
The Supreme Court made abundantly clear early in the life of the nation that the states WERE NOT completely sovereign under the Constitution.
The --People-- have maintained the Union. It belongs to them, not the states. The big four court cases-- Cohens, McCullough, Martin and Chisholm from early in the nation's life make this plain. In all of those cases, the nature of the government is emphasized:
"Here we see the people acting as the sovereigns of the whole country; and in the language of sovereignty, establishing a Constitution by which it was their will, that the state governments should be bound, and to which the State Constitutions should be made to conform. Every State Constitution is a compact made by and between the citizens of a state to govern themeselves in a certain manner; and the Constitution of the United States is likewise a compact made by the people of the United States to govern themselves as to general objects, in a certain manner.
By this great compact however, many prerogatives were transferred to the national Government, such as those of making war and peace, contracting alliances, coining money, etc."
--Chief Justice John Jay, Chisholm v. Georgia 1793
"In the case now to be determined, the defendant, a sovereign state, denies the obligation of a law enacted by the legislature of the Union...In discussing this question, the counsel for the state of Maryland deemed it of some importance, in the construction of the Constitution, to consider that instrument as not emanating from the people, but as the act of sovereign and independent states. It would be difficult to maintain this position....
--John Marshall, majority opinon McCullough v. Maryland 1819
"That the United States form, for many, and for most important purposes, a single nation, has not yet been denied. In war, we are one people. In making peace, we are one people. In all commercial regulations, we are one and the same people. In many other respects, the American people are one; and the government which is alone capable of controlling and managing their interests in all these respects, is the government of the Union. It is their government and in that character, they have no other. America has chosen to be, in many respects, and in many purposes, a nation; and for all these purposes, her government is complete; to all these objects it is competent. The people have declared that in the exercise of all powers given for these objects, it is supreme. It can, then, in effecting these objects, legitimately control all individuals or governments within the American territory.
The constitution and laws of a state, so far as they are repugnant to the constitution and laws of of the United States are absolutely void. These states are constituent parts of the United States; they are members of one great empire--for some purposes sovereign, for some purposes subordinate."
--Chief Justice John Marshall, writing the majority opinion, Cohens v. Virginia 1821
"The constitution of the United States was ordained and established, not by the states in their sovereign capacities, but emphatically, as the preamble of the constitution declares, by "the people of the United States."
-Justice Story, Martin v, Hunter's Lessee, 1816
The sovereignty of the United States rests on the people, not the States.
It was dishonorable for the slave holders to wait 40 + years and then say they disagreed.
Walt
It was equally dishonorable for the north to invade the south when the south exercised their right to leave the union.
The cases said that the power rests entirely with the people and not with the states, well the people of the south wanted out. They should have been let leave.
Regardless of what the laws stated at that time, the OATH that REL swore to was to the states (plural) not to the nation. They should have rewritten the oath if they meant it to be national.