Barbarians by Robert W. Chambers

o this is what happened to the dozen-odd malcontents who could no longer stand the dirty business in Europe and the dirtier politicians at home.
There was treachery in the Senate, treason in the House. A plague of liars infested the Republic; the land was rotting with plots.
But if the authorities at Washington remained incredulous, stunned into impotency, while the din of murder filled the world, a few mere men, fed up on the mess, sickened while awaiting executive galvanization, and started east to purge their souls.