Six eminent biographers explain how they reconstruct other people's lives, and takes us through a gallery of Amer. lives. David McCullough talks of going to Missouri to find "The Unexpected Harry Truman." Richard Sewall describes his 20-year search for Emily Dickinson. Paul Nagel tells us about the 4 generations of "The Adams Women." Ronald Steel recalls how the life of the biographer can become entwined with that of his subject. Jean Strouse discusses the fact that "there are two reasons why a man does anything: a good reason and the real reason." Robert Caro reveals the frustrations of trying to unearth the true facts about a man (Lyndon Johnson) who wanted to conceal them.