'... if the authors of the Hartford Convention believed that "gross, deliberate, and palpable violations of the constitution" had taken place, utterly destructive of their rights and interests, I should be the last man to deny their right to resort to any constitutional measures for redress. But, sir, in any view of the case, the time when and the circumstances under which that convention assembled as well as the measures recommended, render their conduct, in my opinion, wholly indefensible. ... '... The point in contention is that members of the union, during war, resort to a convention. Not that secession is illegal itself.
Secondly, the speech you cite is from 1830. Why not cite what was said during that time itself:
The papers teemed with accusations against the south and the west, and the calls for a dissolution of all connection with them were loud and strong."If you do not wish," said a reverend clergyman, in a sermon preached in Boston, on the 23d July, 1812, "to become the slaves of those who own slaves, and who are themselves the slaves of French slaves, you must either, in the language of the day, CUT THE CONNECTION, or so far alter the national compact as to insure to yourselves a due share in the government," (OliveBranch p 319.) "The Union," says the same writer, (p. 320,) "has been long since virtually dissolved, and it is full time that this part of the disunited states should take care of itself."
In 1814 New Englanders at the Hartford Convention were making thinly veiled threats at secession in protest to 'Mr. Madison's War." Then, Southerners struck the nationalist pose (emphasis added) (Emory M. Thomas, The Confederate Nation, 1861-1865)
Nullification was seen as a legal alternative to secession.
As for going back to the early 1800's, the fact is that the act was considered treasonous, even as late as 1861 when Lee was writing his son.