“Lee may have been a traitor...”
Lee was not a traitor. Traitors do their deeds in secret. Lee went with his state, chose not to be a traitor to his state. Back then, state citizenship trumped national citizenship. You had to be a citizen of a state before you were a citizen of the nation.
There was no naturalization or citizenship for states.
Anyone could move anywhere in the US as a US citizen.
Lee couldn’t stand up for his own convictions and took the Rino route to go along to get along.