I am flying American to Jamaica but I have a layover in Philadelphia, do I check in via domestic or international? ATL to Philadelphia to Jamaica

Just check in with American they have the details of your flight and can guide you.

Normal check in when you leave ATL

Check in is your final destination

Best way to know for sure is call the airport. I'm sure they be happy to help you.

International i would think..if your getting your luggage back it might be domestic. I would think how long your layover is as deciding factor.