You are correct, SHJack. So after your buddy visit, you will simply return to the airport, enter TSA security, where you have to produce your boarding pass and your passportID, and then head out to the gate for your next flight, be it international or USdomestic.
I've yet to see a US airport where the procedure is any different. The variations come at the point where you enter the US originally -- some are reasonably organized (IAH) and others are simply 3rd-world chaotic (EWR).