We had so much fun with this yesterday, let's recap and start again with a more honest focus on one of the most resilient and fertile questions of American history: Was the Civil War fought over slavery?

My thesis (and this is key): The North did not begin the war to end slavery, but the South began the war to protect slavery.

The Election of 1860, in which the Republican Party swept 18 out of 18 free states, relegated the South to minority status. For several decades, a vast majority of Southerners had agreed that Northern rule was the end of “liberty” as they knew it. The new regional party, unlike the national parties that had come before, was so far removed from Southern sensibilities that it was not even on the ballot in most Southern states in 1860.

The election of Abraham Lincoln was an earthquake. Even as Lincoln promised that he would leave slavery undisturbed in the places in which it already existed, the South could not afford to accept that pledge. For at least a decade leading up to the watershed election, the South had asked for assurances, and, now, instead, they got Lincoln. The man who saw slavery as a great evil that must eventually be extinguished. “A House Divided Against Itself Cannot Stand.” The Party of “Free Soil, Free Labor, Free Men” was now ascendant, and “Spot Resolution” Lincoln was at the crest of the wave.

The secession crisis of 1860-61 was not unlike previous standoffs between the two sections. Ten years earlier, the South had conducted furious preparations to leave the Union over the disposition of the slave question in the newly acquired territories in the West. The result of the turmoil then was the Compromise of 1850, on which the South reneged four years later, when Southern leaders demanded slavery be extended into the Kansas territory, in violation of the thirty-four year-old Missouri Compromise.

But the election of Lincoln, and more importantly the unprecedented regional majority, proved the final straw. As a last gasp, the South demanded that Lincoln agree to the extension of slavery into the West. Lincoln refused. And the War came.

Lincoln did not bring the Union into the fight to end slavery. He is famous for saying:

"My paramount object in this struggle is to save the Union, and is not either to save or to destroy slavery. If I could save the Union without freeing any slave I would do it, and if I could save it by freeing all the slaves I would do it; and if I could save it by freeing some and leaving others alone I would also do that."

Having said that, the war did end slavery.

Was the South's fight merely to protect state rights? Again, the great question: What right were the seceding states defending? The right to secede? What right was in danger in the winter of 1860-61? What had changed? What was behind the secession at that moment?

Ironically, the failed secession was the end of state sovereignty as a viable counterweight to the power of the central government. Ironic, that is, because, in effect, state rights theory committed suicide. From the Civil War, the federal government emerged ascendant. No one would ever argue that the states were co-equal seats of authority again. No one would ever entertain the notion that secession was a possibility again.