Captivating disgruntled voters, third parties have often complicated the American political scene. In the years before the Civil War, third-party politics took the form of the Know Nothings, who mistrusted established parties and gave voice to anti-government sentiment. Originating about 1850 as a nativist fraternal order, the Know Nothing movement soon spread throughout the industrial North. In Beyond Party, Mark Voss-Hubbard draws...