Ever heard of PSM? No?
Portsmouth, NH has its own airport, and is the only actual International airport in New Hampshire. Manchester, NH does have US Customs, but is located in Signature FBO, which is why it’s a regional airport.
Portsmouth has a small Terminal, which houses U.S Customs, which marks it International, despite not having Regular International Service (Not counting Atlas Air and other charters).
I hope you enjoy the video. PSM is one of those rare airports with a lot of potential to grow.
Side Note: I made this little video as I was waiting to start my Background check for me to get a Customs seal on my Badge. Hoping to start soon!