STUART, CUSTER, KILPATRICK AND FARNSWORTH: TOPOGRAPHY, MILITARY GEOLOGY AND DRAMA OF THE EAST AND SOUTH CAVALRY FIELDS AT THE CIVIL WAR BATTLE OF GETTYSBURG, ADAMS COUNTY, PENNSYLVANIA - JULY 3, 1863

On the 3^rd day of the battle of Gettysburg, two dramatic cavalry sideshows played out to the east and south of Pickett’s Charge upon the Union Infantry position on Cemetery Ridge. The topography and geology of the Triassic/Jurassic Gettysburg rift basin were important factors in both engagements.

The low rolling terrain of the East Cavalry Field is underlain by gently west-dipping red shales and sandstones of the Triassic Gettysburg Formation—excellent terrain for conducting cavalry actions. But then as now open and treeless, it also provided limited cover and concealment for either side. Here Confederate Major General J. E. B. Stuart attempted to disrupt the Union supply route as Pickett’s Charge was going on. His horsemen, however, were clearly observed moving to the Union rear. Stuart’s forces outnumbered those of his Union cavalry counterpart, Brigadier General David Gregg, who took position along the Hanover Road leading southeast out of the town of Gettysburg. Gregg, however, had an “ace in the hole”: Stuart’s attempt to flank the Union forces was thwarted mainly by a newly promoted brigadier general, George Armstrong Custer, whose Michigan brigade was newly added to his force from the cavalry contingent under Brigadier General Judson Kilpatrick stationed to the south. After a series of bloody charges and counter-charges, Stuart ultimately had to withdraw.

The last great tragedy of the battle of Gettysburg took place a little later on the boulder-strewn, openly wooded (at the time) South Cavalry Field, a swale between Little Round Top to the north and Big Round Top to the south. The topography here, developed on the Jurassic York Haven Diabase, is totally unsuited to cavalry action. Late in the day, General Kilpatrick ordered Elon Farnsworth, also newly promoted to brigadier general, to lead an ill-fated charge against well-placed Confederate infantry in the last action of the battle of Gettysburg. Farnsworth, who considered his mission almost suicidal, was killed—and his attack, designed to support an aborted Union counterattack, accomplished nothing. Had Custer not moved north to serve under Gregg, perhaps he would have been the one to fatally carry out Kilpatrick’s order to charge through the boulders of South Cavalry Field. Thus, one of the most iconic events in American history might never have occurred 13 years later!