Geology and Generals: How Geology influenced the Gettysburg Campaign (Part I.)

“Hence the saying: If you know the enemy and know yourself, your victory will not stand in doubt; if you know Heaven and know Earth, you may make your victory complete.” The Art of War, by Sun Tzù

In 1863, after more than two years of Civil War, the Confederate Army of Northern Virginia launches a decisive attack towards the north, in direction of the town of Harrisburg in Pennsylvania. Spotted by the Union Army a skirmish near the small farm town of Gettysburg starts, soon escalating into one of the bloodiest battles in U.S. history. In three days (July 1 to July 3) nearly 50.000 Americans were killed or wounded.  The outcome of this military campaign and battle was strongly influenced by geological events almost one billion years in the making.