To say that any State may at pleasure secede from the Union, is to say that the United States are not a nation because it would be a solecism to contend that any part of a nation might dissolve its connection with the other parts, to their injury or ruin, without committing any offense. Secession, like any other revolutionary act, may be morally justified by the extremity of oppression; but to call it a constitutional right, is confounding the meaning of terms, and can only be done through gross error, or to deceive those who are willing to assert a right, but would pause before they made a revolution, or incur the penalties consequent upon a failure.

Proclamation against the Nullification Ordinance of South Carolina (11 December 1832)

President Jackson's Proclamation against the Nullification Ordinance of South Carolina