It is likely Vaccinium corymbosum. Look up some pictures of that and see if it matches.

Here is a link that might be useful: Vaccinium corymbosum distribution in PA

I agree with esh_ga - it looks like Highbush Blueberry. I looked at the USDA distrubution link provided by esh and it shows a few counties without a record for Highbush Blueberry. I bet you could find Highbush Blueberry in every county in PA, except perhaps very near Philly where it might be gone due to development. The USDA map is based on herbarium specimens or some other scientific record, and such records are always spotty. In reality, the distribution of a fairly widespread plant like Highbush Blueberry is probably not as spotty as the map indicates.

If we're right about the identification the bush should have edible berries in the summer. If they don't look like blueberries, we are probably wrong on the ID and I wouldn't eat them (but I don't think we're wrong).