"Confederates who precipitated the bloodiest war in the nation’s history"
Begging the author's pardon, but weren't ALL the battles in the Civil War fought on Southern territory? Let's be honest, it wasn't a "civil" war, as the south wasn't attempting to overthrow the federal government. It was a war perpetrated by the north against the south to prevent secession. Therefore, the blame for the 600,000 deaths must be laid on Lincoln and the North.
Further, nullification and secession are American principles, enshrined in the Declaration and the Constitution. A state may nullify unconstitutional actions of the federal government, and, when that fails, may secede and reestablish itself as a sovereign nation.