Basler, Vol. II, The Collected Works of Abraham Lincoln (1953), p. 115.
On January 12, 1848, Lincoln, in an address before the United States House of Representatives, stated:
Any people anywhere, being inclined and having the power, have the right to rise up, and shake off the existing government, and form a new one that suits them better. This is a most valuable — a most sacred right — a right, [p270] which we hope and believe, is to liberate the world.
And clearly the Southern states were so inclined but the lacked the power to successfully rise up and shake off the existing government.