John Brown was the first American to be executed for treason. While Preston was jubilant in his celebration of the inexorable justice of the law in 1859, he and his fellow Virginians would soon have reason to reconsider.
The punishment for treason in America had never been clear. To guard against leaders who might expand the definition of treason to sweep in political opposition, the Founding Fathers had specified that only levying war against the United States or giving “aid and comfort” to an enemy could be considered treason. But they had not defined a penalty for treason, leaving that to be determined by Congress. Most state constitutional conventions followed the lead of the Founding Fathers and wrote similar guidelines into their fundamental state law.
As men jockeyed for control of the government in the chaotic early years of the Republic, several men ran afoul of the federal and state treason clauses, but they did not pay the ultimate price for their missteps. Two men were convicted of treason against the federal government during the Whiskey Rebellion in the 1790s; President Washington pardoned them both. In 1838, Joseph Smith and five other Mormon leaders were charged with treason against Missouri for their part in the violent struggle between Mormons and non-Mormons in the state; they escaped before trial. Thomas Wilson Dorr was convicted of treason against Rhode Island for his part in the Dorr Rebellion of the 1840s and was sentenced to hard labor for life, but a popular protest won him amnesty after serving a year.
So when a Virginia court convicted John Brown of treason for his attempt to launch a war to end slavery and decided that he would hang for his crime, it set a precedent. Virginians like Preston applauded the decision. “Law had been violated by actual murder and attempted treason,” Preston gushed to his wife in a letter reprinted in the local newspaper, “and that gibbet was erected by law, and to uphold law was this military force assembled…. So perish all such enemies of Virginia! All such enemies of the Union! All such foes of the human race!”
But in just over a year, Virginians themselves would take up arms against the federal government. Men like Preston, who became an aide-de-camp to Stonewall Jackson, had to wonder if the precedent of hanging John Brown for treason might, ironically, come back to haunt the very men who had set that precedent in the first place.