What If?

The date is July 1st, 1863. Traveling through Pennsylvania, you cross through a town called Gettysburg. By morning, General Henry Heth was the first General to lead an army into the town. Heth was hoping to seize supplies from the Union, instead you hear gunshots. Three brigades of Union cavalry attack General Heth and his army.
"We have them outnumbered!" yells Heth.
The battle goes on and by mid-afternoon your reinforcements arrive. Close to 24,000 confederate soldiers are faced with about 19,000 Union soldiers. You however, are still traveling.