It is a mistake to say there is no right to secede. The right of the southern states to secede was denied by force of arms, not by law. The example of 1861, therefore, should not be used.
The right to secede is found in the Declaration of Independence (1776):
"That whenever any form of government becomes destructive to these ends, it is the right of the people to alter or to abolish it, and to institute new government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their safety and happiness."
Dr. Williams is correct.