Everybody knows the story of what happened that first day of Gettysburg. James Archer's birgade gets defeated by John Buford, Archer gets captured. But what if it had gone the other way? What if Buford had been beaten by Archer? Could it have changed things alot?
It probably would have changed the Battle of Gettysburg from a Major Battle to a skirmish. If Buford had failed to hold off the Confederates at Gettysburg long enough for the Infantry to arrive, then Meade would probably have formed up his army along the Pipe Creek Line. Perhaps Buford could have fallen back and drawn the Confederates with him to the Pipe Creek Line and insured that Lee attacked the AOP there. In any case, the Pipe Creek Line has been said to have been even stronger than the Culps Hill/Cemetery Ridge/LRT line held by the Union at Gettysburg, if so, and if Lee attacked Meade there, the Confederate losses may have been even greater.