“Hang him on that tree.”

The Constitution’s definition of treason against the United States (Article III, Section III) states: “shall consist of levying War against them, or in adhering to their Enemies, giving them Aid and Comfort.” Note that levying war is against “them”; John Brown was tried for treason against the State of Virginia. The Confederate Constitution was identical, defining treason as against a State, not a government or nation. Anyone going over to the enemy, black or white, for whatever reason, was guilty of treason and faced the fatal consequences.
Bernhard Thuersam, www.Circa1865.com   The Great American Political Divide

The Consequences of Treason

“I was sitting on my horse near General [JEB] Stuart, who had put in the skirmishers, and was now superintending the fire of his artillery, when a cavalry-man rode up and reported that they had just captured a deserter.

“Where is he?” was Stuart’s interrogatory.

“Coming yonder, General.”

“How do you know he is a deserter?”

“One of my company knew him when he joined our army.”

“Where is he from?”

“_____ county.” And the man mentioned the name of a county of western Virginia.

“What is his name?”

“M____.” (I suppress the full name. Some mother’s or sister’s heart might be wounded.)

“Bring him up,” said Stuart coldly, with a lowering glance from the blue eyes under the brown hat and black feather. As he spoke, two or three mounted men rode up with the prisoner. He was a young man, apparently eighteen or nineteen years of age, and wore the blue uniform, tipped with red, of a private in the United States Artillery.

“You say he is a deserter?”

“Yes sir; acknowledges that he is M___, from that county,; and after joining the South he deserted.”

A kinder-hearted person than General Stuart never lived; but in all that appertained to his profession and duty as a soldier, he was inexorable. Desertion, in his estimation, was one of the deadliest crimes of which a human being could be guilty; and his course was plain – his resolution immovable.

“Where are you from?” [said Stuart].

“I belonged to the battery that was firing at you, over yonder, sir.”

“Did you belong to the Southern army at any time?”

“Yes sir.”

“So you were in our ranks, and you went over to the enemy?” he said with sort of a growl.

“Yes sir,” was the calm reply.

Stuart turned to an officer, and pointing to a tall pine near, said in brief tones:

“Hang him on that tree.”

(Outlines from the Outpost, John Esten Cooke, Richard Harwell, editor, Lakeside Press, 1961, pp. 301-305)