Without a photo of the flowers, I believe that it will be impossible to identify.

My apologies, I see that you do have the flower included in the photos. So, with that, I'll say that you'll need better photos of the flowers.

I see that you're in Pennsylvania. Clematis terniflora is naturalized & becoming increasingly invasive in Pennsylvania. In Philadelphia & suburbs, where I work as a gardener, it's one of our most persistent weeds.

Try going into "clematis.com"...follow the trail to picture identification using your plant's flowering time, height.

The time of bloom can squeeze the varieties that bloom at the same time....the height just a bit more info.
Considering there are over 1000....that's one thousand...varieites of clematis its rather most difficult to identify by leaf....a color photo of its bloom will nail it down.