That is a young Dove. It's pattern looks a bit like a juvenile Common Ground-Dove, but in PA it is much more likely to be a juvenile Mourning Dove.

You should be aware it is illegal for you to possess that animal without a state/federal permit. This includes possession in order to "rescue" the bird.

Generally, if you find a juvenile bird like this you should leave it where you found it. The adults will continue to feed, defend and care for it, even if it is on the ground.

The best approach to a baby bird on the ground is to put it back in the nest if possible or on a branch if it seems that it has just fledged. Second best for an obvious too early fledge is to rig a small container solidly just above where the baby is sitting, but out of immediate harm's way from pets and other interested individuals, animal and human. You can watch with binoculars and shoo away those unwanted visitors and to see if the parents are returning to the baby--they may be encouraging them to fly farther afield by withholding feeding. After a prolonged period of time without parental attention, relative to the age and species the baby could be taken to a rescue center. Call them first before transport. Not every center takes every species of animal but they will advise you. Be aware of nest bird parasites.