Grapes?

We have this vine growing at a corner of the yard.  It climbs way up into the two or three trees that are near it.  I knew it was some kind of grape vine, but up until this summer, it has never had any fruit on it.

This year it is LOADED with some kind of grape.  I've eaten a couple and didn't get sick, so I guess they are edible, but they are kind of sour.  The skin is thick and the middle part surrounding the seeds is kind of a slimy ball.  They aren't like a grape that you buy at a grocery store, but the taste is familiar and they leave a familiar sort of ...scratchy feeling in the back of my throat, so I must have eaten them as a child at some time.  I admit, I've always been one to pick and eat something just to see what it taste like.  There's a little clover-like plant that grows a tiny little pod that looks like an okra that I've eaten since I was a child.  It reminds me of pickles.  Not that I going around grazing like a goat, but, you know, if there's one around, I might pick it and eat it just for nostalgia's sake.

Anyway, could I make something with these?  Jelly maybe, with lots of sugar?  Does anyone know what they are?

Annnnd, yay for friends with tree farms!  We just got these trees from a friend who is going out of the tree farm business.  They are red oaks, lace bark elms, a Japanese Maple, and a couple of crepe myrtles.  We'll be planting several of the oaks around the barn for shade.  The maple is for an ornamental in the yard by the house.  I'm not sure where I'll put the crepe myrtles.  I need to find out how big they'll get before I decide - maybe between us and the neighbors for privacy.