I’d speculate that we could very easily be describing the Battle of Pipe’s Creek that took place in the first week of July 1863 as an Alternative History to the Battle of Gettysburg. This could easily be the history of the USA if BG Buford had done just his job – instead of more than his job!
BG Buford had been dispatched to locate and fix the position of Lee’s Army. He essentially accomplished that task when he spied the party of scavengers moving west from Gettysburg. WHATIF he had simply returned to camp and made his report to LTG Reynolds instead of concocting the ambush.
Had Buford not been blocking the way on July first, Heth’s division would have marched for a few hours and established a bridgehead at the north end of the Baltimore Pike. Over the course of the day, the rest of Hill’s Corps would have encamped in the area of Culp’s Hill. Late in the afternoon, Ewell’s Corps would have arrived from the north. Longstreet was still the better part of a day’s march to the west.
Still not exactly sure where Meade’s Army was located, Lee would likely have sent Hill down the Pike and Ewell south on the Emmittsburg Road, running roughly parallel to it. This could have happened on July 2 or Lee could have waited for Longstreet to consolidate his force at Gettysburg before proceeding on 3 July.
The bluff overlooking Pipe’s Creek where Hooker had decided to make his stand blocking the Baltimore Pike, is roughly 14 miles south of Gettysburg. Emmittsburg where LTG Reynolds was encamped with two Union Corps is only 10 miles SW of Gettysburg. Meade would have recalled his easternmost Corps as Early abandoned his march to York. He would have been waiting near Taneytown with three Union Corps.
Exactly where the first clash would have occurred would have depended on the time of departure and the rate of march of Hill and Ewell’s Corps. It’s quite likely that two battles would be been fought almost simultaneously only a few miles apart.
GEN Lee would need to make vital decisions of how and where to move his army south.