We are headed to Puerto Vallarta via a plane change/layover in Chicago from Philadelphia airport. Our first flight to Chicago departs at 6 AM. At what time should we be at the Philadelphia airport? I know that for later flights, we are required to get there two hours early but I'm not sure what time airline representatives are actually present in the morning. Also, does anyone know if we should go to the international terminal vs regular terminal? I'm thinking international because our ultimate destination is Puerto Vallarta, MX but then again, the initial flight is to Chicago. Is there somewhere online that I could go to research this question? Any guidance is greatly appreciated. I am flying US Airways to Chicago and United to PV. Full flight plan was scheduled via one confirmation.