Compared with Confederate soldiers, a challenge that Union soldiers faced during the Civil War was

The Civil War largely took place in the south; the most northern battle was in Pennsylvania. Therefore, Confederate soldiers were fighting on home turf, land they knew well, while northern soldiers were the "away team." Home court advantage belonged to the Confederates, and defense is always easier than offense; all you have to do is hold what you already have. The Union soldiers had to take land instead of simply hold it. Does that make sense?