NPS Interpretive Ranger and author, Troy Harman, came by the studio for the first time ever to talk about his latest book, "All Road Led to Gettysburg." As with most of Troy's work, "All Roads..." compels the reader to readjust his or her thinking/approach to studying the battle of Gettysburg. Just how much do roadways, railways and waterways factor into the movements of armies and the locations of the inevitable battles they fought, like the one at Gettysburg? History changes on the smallest factors, and, like "An Environmental History of the Civil War", Troy's book shows us just how much these seemingly insignificant things are far more integral to how history unfolds.