Fourth Circuit Court of Virginia was the jurisdiction Andrew Johnson wanted for the treason trial of Confederate President Jefferson Davis.

Military officials wanted to try him in their courts. The authorities debated over the jurisdiction for two years while Davis was imprisoned. Johnson knew a military trial would make Davis a martyr. Chase refused to hear cases in the Virginia Circuit while the State was still under the military government and not until the writ of habeas corpus was restored. When Chase finally sat at the Davis trial in November 1868 he approved Davis' lawyer's argument that the 14th Amendment that had recently gone into effect applied to Davis. In December Johnson issued a general amnesty. At the next session of circuit court, Chase discharged Davis on the grounds he was included in the pardon and COULD NOT BE TRYED EX POST FACTO.20]

All I did to this post was cap the last part.

http://odur.let.rug.nl/~usa/B/spchase/chase05.htm

Now think about this a minute,,,,,if the 14th amendment made secession treason, then secession waws not illegal prior to the time of the law being passed. Though Chase did not come out and say it in those terms, this is what he meant.