"The Battle of Gettysburg in south-central Pennsylvania was the largest ever fought on American soil and one of the most significant in its consequences. Moreover, more clearly than most, it demonstrates the roles which underlying geology and surface topography can play in military actions. Early Mesozoic happenings produced the rocks underlying and shaping the Gettysburg landscape, which influenced the flow of battle and thereby impacted the course of American history." -- p. 1.
Originally published as a section of: Boulder, Colo. : Geological Society of America, 2006, as part of: Excursions in geology and history : field trips in the middle Atlantic states. 9780813700083