GEOLOGIC ANALYSIS OF THE BATTLE OF CHANCELLORSVILLE USING GIS/REMOTE SENSING TECHNOLOGY

The Battle of Chancellorsville in May 1863 is widely regarded as one of the most important engagements in American military history. Confederate General Robert E. Lee defeated a numerically superior Union force by sending General Thomas J. (Stonewall) Jackson on a flanking march and attack that virtually destroyed the Federal right wing and any hope of northern victory.. We have geologically analyzed the battle using GIS/remote sensing technology in combination with troop position maps, a geologic map, and digital elevation models. The engagement was fought primarily across a number of central Virginia Piedmont terranes, although some action occurred on Tertiary outliers of Coastal Plain sediments. A “time lapse” series of maps showing Union and Confederate movements during the main phases of the battle reveals a number of connections between troop positions and geology, including the following: (1) Jackson’s assault from the west was launched from high ground located along the contact between an island arc terrane and a successor basin; (2) the main components of the Union army were forced into a triangular-shaped pocket outlined by the Long Branch thrust fault (an important terrane boundary) and a large, unnamed lineament; and (3) Confederate forces advanced from a ridge capped by Tertiary sediments to hem in Federal forces on the eastern side of the battlefield. In addition, we produced a “flyover” of Jackson’s flanking march and attack as seen from both Confederate and Union perspectives.