Originally Posted by
Hartington
Atlanta has a landside terminal and then a series of subsidary terminals linked together by an underground train. International arrivals use the terminal furthest away from the landside terminal. You arrive, get off your plane, go through immigration, pick up your bags, go through customs. So far so normal.
However, to get anywhere else you then have to get on the underground. It doesn't matter if you're catching another plane or trying to get into Atlanta you take the train. Now, the train is the same train that passengers coming from landside to the planes use. So, they go through security before boarding the train AND SO DO YOU.
This is the same at any connecting point in the US. If you're an international arrival, you clear immigration, collect bags and clear customs at the connecting point. Then you hand your checked bags back to the airline before going to your onward flight.
And then after you have handed your checked bags back, you
must clear security. This happens at
every US connecting point. It is not specific to Atlanta. If you've had access to your checked baggage, you are by definition no longer secure and you must be security screened again.
That said, some of my worst US immigration experiences have been at Atlanta. I think that the OP may have misinterpreted something said by SeenItAll as positive advice that he should connect at Atlanta. I don't think that's what SeenItAll meant.