"Susan B. Anthony must die," the letter says. The year is 1891, a time of tremendous social unrest. Anarchists were attempting to force change by overthrowing governments around the world. The Civil War was long over, and slavery was outlawed, and yet the racism and social conditions that made slavery possible still existed. The Eugenics movement, which foreshadowed Adolph Hitler's "Master Plan," advocated the forced sterilization, or even euthanasia,...