The historical periods I like to learn about aren't so much costume dramas as slasher flicks. The French Revolution is a favorite because it features the beloved plot of carnage in service of democracy, but I prefer American history. And if I had to pick my pet domestic bloodbaths, nothing beats Salem or Gettysburg. I'm a sucker for Puritan New England and the Civil War. Because those two subjects feature the central tension of American life, the conflict between freedom and community, between individual will and the public good.