Okay, I am confused. If we are flying out of Rome's Leonardi De Vinci Airport and headed for Amsterdam before the US are we on a international flight or a domestic flight? I don't want to be at the wrong terminal.
OK here it goes (I think). Google the airline you are flying on, that is, the carrier you are taking from Rome to Amsterdam. This will tell you the terminal the carrier you are using departs from. If you are flying from Rome to Amsterdam for a few days visit it's a domestic (EU) flight. Transiting Amsterdam on the way home to the U.S. (i.e. not leaving the airport) your international carrier to the U.S. may well be in a different terminal when you land in Amsterdam but you will not need to leave the secure area.