A few weeks ago, I opened up Professor Cynthia Nicoletti's recent book, Secession on Trial: The Treason Trial of Jefferson Davis. I didn't expect that I'd spend the next few weeks fiercely poring through it, but I've found myself unable to put it down or stop thinking about it.

The book tells the story of the federal government's attempt to prosecute Jefferson Davis, the former president of the so-called Confederate States of America, after the end of the Civil War. (If, like me, you found yourself thinking, "huh, I didn't even know that there was a treason trial of Jefferson Davis," I will spoil the ending -- the trial never comes, and Davis receives the benefit of the general amnesty from President Johnson.)

Nicoletti argues that at the time, the legality of secession was far less settled by the war than we like to think. If secession was lawful, Jefferson Davis might no longer have been a citizen of the United States subject to the U.S. law of treason, and the threat of that defense -- and the possibility that it might succeed in front of a jury -- kept the federal prosecutors quite nervous about pressing the issue. That, among other things, is how Davis's lawyers managed to run out the clock until the amnesty.

Read more at The Volokh Conspiracy