When I flew Vancouver (BC) to Sydney (AU) we stopped to refuel in Honolulu. Apparently, because of safety rules, although nobody was boarding or departing the flight there, we all had to get off while they refueled - then go through customs, outside, back in through TSA, to reboard our flight.
For the OP - very logically, is the flight ONLY to Minneapolis? My guess is that the Dallas stopover allows some to get off and other passengers to get on. Otherwise, why bother? It’s no problem to fly direct but this way takes care of two flights. So a plane-load of foreign arrivals gets off, goes through customs (plus the airplane gets swept) and then it becomes a domestic flight.
I used to fly thru a “international” US airport with no customs service. When flying in, you’d go thru US customs at the departure airport (e.g., Toronto).
Just checking, apparently the outbound US customs checking thing is still a deal at Pearson.
So, no, you don’t always go thru customs at the first US airport you arrive at. Simplicity, meet Real Life.
Yeah, that is the preclearance thing mentioned above. As WildaBeast noted, the US airport can’t an airport with absolutely no customs service available, but can be one where passengers don’t typically go through customs.
There are plenty of “international” airports with no customs facilities for commercial passenger flights, but have customs available (sometimes by appointment only) for private flights. Hillsboro airport outside of Portland, OR, doesn’t even have scheduled commercial flights at all, but it has a customs office.
It’s the same in Dublin, Ireland. Hence the popularity of the Aer Lingus flights to Europe. I know the USA would love more preclearance airports, but that’s a lot of valuable space to give up.
That distinction between immigration and customs can make things a little weird in Europe, since the Schengen Zone and the European Union aren’t the same thing, and some countries are in one but not the other.
*The EU is, among other things, a free trade/customs zone.
*The Schengen Zone allows free movement of people with no immigration/passport control between countries.
Norway is in the Schengen Zone, but isn’t a full member of the EU. So when I flew into Oslo with a layover in Stockholm on the way, I went through immigration and got my passport stamped in Stockholm. In Oslo I didn’t need to show my passport since I had flown between two Schengen countries. But I had to go through customs in Oslo, since I had flown from an EU country to a non-EU country.
Before Brexit, the UK was the other way around. When I flew home from Greece with a connection in London last summer, I had to go through EU exit immigration upon leaving Greece. And I had to go through UK entry immigration upon leaving the international part of the terminal in Heathrow (My layover was overnight, so I went to a hotel in another terminal for the night, which required officially entering the UK). But no customs, since I was still in the EU at the time.