If, on the one hand, negro slavery undermined the moral unity and consequently the political integrity of the American people, and if on the other, the South stubbornly insisted upon its legal right to property in negroes, the difficulty ran too deep to be solved by peaceable Constitutional means.

The legal structure of American nationality became a house divided against itself, and either the national principle had to be sacrificed to the Constitution or the Constitution to the national principle.
The significance of the whole controversy does not become clear, until we modify Webster's formula about the inseparability of liberty and union, and affirm in its place the inseparability of American nationality and American democracy.

The Union had come to mean something more to the Americans of the North than loyalty to the Constitution.

It had come to mean devotion to a common national idea,--the idea of democracy; and while the wiser among them did not want to destroy the Constitution for the benefit of democracy, they insisted that the Constitution should be officially stigmatized as in this respect an inadequate expression of the national idea.

American democracy and American nationality are inseparably related, precisely because democracy means very much more than liberty or liberties, whether natural or legal, and nationality very much more than an indestructible legal association.