The United States of America was a union of 34 states in 1861.
R.E. Lee fought against this great union.
Indeed he did, but he could not be a traitor to it, since he never was a resident of any union state.
You want a traitor, go with Paul Revere.
“370,000 United States soldier died in the war.”
Odd that you didn’t use the term ‘American’.
Welcome to FR.
The Union offered command of the army to Robert E. Lee, he discussed his divided loyalties with the highest government officials.
His discussions and resignation were all above board and honorable.