TOM CHAFFIN is the author of, among other books, Giant's Causeway: Frederick Douglass's Irish Odyssey and the Making of an American Visionary; Sea of Gray: The Around-the-World Odyssey of the Confederate Raider Shenandoah; and Pathfinder: John Charles Frémont and the Course of American Empire. His writings have also appeared in the New York Times, the Oxford American, Time, Harper's, and other publications. He lives in Atlanta.