The name Daniel Sickles and the word controversy are synonymous. Any student of 19th century American political history is familiar with Sickles' 1859 murder of Philip Barton Key, the son of Francis Scott Key, who had seduced Sickles' young wife. That murder, because Sickles was at the time a New York Congressman and Key a district attorney for Washington, captured the country's imagination, a front-page event that inevitably ensnarled President James...