Thomas Jefferson, a Character Sketch
On six separate occasions, there were overt acts on the part of the States.
The first occurred in 1798, when Virginia and Kentucky passed nullification resolutions.
The second was the attempt of New England in 1803 to form a northern confederacy, comprising five New England States, and New York and New Jersey. The third was Aaron Burr's wild scheme in the Southwest.
The fourth, the resolution of the New England States to withhold cooperation in the War of 1812.
The fifth, the nullification acts of South Carolina in 1832.
The sixth and last, the effort of eleven states to form the Southern Confederacy. This brought the burning issue to a head and settled the question for the ages to come.