Mr. McCullough talked about his writings and his career and responded to audience telephone calls. He is a Pulitzer Prize-winning historian whose books include, Truman, The Johnstown Flood, Mornings on Horseback, The Great Bridge, and his latest New York Times best-seller, John Adams. He has served as the narrator to Ken Burns' historical documentary, "The Civil War," on PBS, and as the host of its series "The American Experience." David McCullough described his writing process as video was shown of his home in West Tisbury, Massachusetts, on Martha's Vineyard.