The Civil War Trust's map of the battle of Gettysburg - East Cavalry Field
While infantry fighting resumed on the morning of July 3, 1863, Union cavalry under Gen. David McMurtrie Gregg were strongly picketing the intersection of the Hanover and Low Dutch roads--the direct route to the rear of the Union Center with two brigades, with a third, the Michigan cavalry of Gen. George Custer, close at hand. Artillery shells signaled the opening of Confederate attack followed by dismounted fighting on the farm of John Rummell. The Confederate horsemen under Gen. Jeb Stuart launched a series of mounted attacks, each of which was repulsed by a mounted charge from the Federals. After suffering heavy losses, Stuart withdrew his forces. The Union rear was secure.
On July 2, Lee attempted to envelop the Federals, first striking the Union left flank at the Peach Orchard, Wheatfield, Devil’s Den, and the Round Tops with Longstreet’s and Hill’s divisions, and then attacking the Union right at Culp’s and East Cemetery Hills with Ewell’s divisions.
While the Confederates assaulted the Union center, Federal cavalry commander Gen. Alfred Pleasonton issued an ambiguous directive to his subordinate on the southern part of the field, Gen. Hugh Judson Kilpatrick. Kilpatrick, with an order to strike the enemy "at the earliest opportunity," launched a series of piecemeal mounted attacks against the Confederates astride the Emmitsburg Road and at the foot of Big Round Top.