Really? How many hanged?
Anyone brought to the bar of justice, as in Ex Parte Bollman?
The Hartford Convention did not advocate secession and the day after they submitted their demands to the Federal gov't, it was learned that the peace treaty with the British had been signed.
Still the Federalists never shook their association with the Convention which was viewed as treasonous since the nation was at war.
It was the same taint of treason that the Democratic Party had to fight against after the Civil War.
Considering some of their post-Civil War history, (Wilson, FDR, Truman, Carter, Clinton), the charges can be considered as having a basis of plausibility.