July 6th, 1863 turned out to be a fairly consequential day as General Robert E. Lee's Army of Northern Virginia continued its retreat through Monterey Pass toward the Potomac. Union cavalry under Generals Judson Kilpatrick and John Buford attack Jeb Stuart's cavalry at Hagerstown and John Imboden's improvised defense at Williamsport. General George G. Meade finally decides to mount a real pursuit of the Confederates.