That is not fact merely because you say it is. Lincoln, Jackson, Buchanan, Clay, Webster, and Robert E. Lee himself are just a few of the men who all knew that secession was illegal.
28 nays to 18 yeas
So it appears that 61% knew their Constitution well enough to know that such an act was unnecessary.
Correction: Robert E. Lee did not believe secession was needed, and opposed it until Virginia left. He never felt it was unlawful.
Really?! First of all, the federal government was created by the several States. It only had the authority that was delegated to it. Our federal ( not National ) Constitution is a compact amongst individual Sovereign entities. Webster understood this fact when he said:
If the South were to violate any part of the Constitution intentionally and systematically, and persist in so doing, year after year, and no remedy could be had, would the North be any longer bound by the rest of it? And if the North were deliberately, habitually, and of fixed purpose to disregard one part of it, would the South be bound any longer to observe its other obligations? I have not hesitated to say, and I repeat, that if the Northern States refuse, willfully and deliberately, to carry into effect that part of the Constitution which respects the restoration of fugitive slaves, and Congress provide no remedy, the South would no longer be bound to observe the compact. A bargain cannot be broken on one side and still bind the other side.
As did James Buchanan:
The question fairly stated is: Has the Constitution delegated to Congress the power to coerce a state into submission which is attempting to withdraw or has actually withdrawn from the confederacy? If answered in the affirmative, it must be on the principle that the power has been conferred upon Congress to declare and to make war against a state. After much serious reflection, I have arrived at the conclusion that no such power has been delegated to Congress or to any other department of the federal government. It is manifest upon an inspection of the Constitution that this is not among the specific and enumerated powers granted to Congress, and it is equally apparent that its exercise is not “necessary and proper for carrying into execution” any one of these powers. So far from this power having been delegated to Congress, it was expressly refused by the Convention which framed the Constitution.
Journal of the Federal Convention, Vol. 1, May 31, 1787:
Mr. MADISON observed, that the more he reflected on the use of force, the more he doubted the practicability, the justice and the efficacy of it, when applied to people collectively, individually. Any union of the States containing such an ingredient seemed to provide for its own destruction. The use of force against a State would look more like a declaration of war than an infliction of punishment; and would probably be considered by the party attacked as a dissolution of all previous compacts by which it might be bound.