[Alter Kaker]

For example, General Ambrose Burnside arrested Copperhead Congressman Clement Vallandingham and threw him in prison without formal charges for violating martial law. Lincoln vacated the conviction and instead expelled Vallandingham into confederate-held territory, effectively banishing him from the United States.

[Svartalfiar]

Lincoln vacated the conviction and instead expelled Vallandingham into confederate-held territory, effectively banishing him from the United States.

And yet, by Union arguments the South wasn't allowed to secede, and they were all still part of these US, so he wasn't actually expelled from these US, right?