Originally Posted by
Fanjet
Bags at the non-U.S. origin always get tagged to the final destination. However, U.S. regulations require all passengers at the U.S. point-of-entry to retrieve their checked baggage after passing through immigration before being able to proceed into the main terminal area of that airport, and after passing through customs. And there are luggage "re-check" counters just prior to the exit into the non-sterile area. I'm actually quite surprised that on your previous transit connection at MIA you did not have to do this; and that your bages were automatically transfered from your inbound intl flight to your outbound one to EZE. Was your departure city from Europe DUB by any chance?
International to international bags connecting through MIA and DFW and tagged with the red connection tag can be routed through without being claimed and rechecked at the US connecting point. This is airport specific however, and the bags have to be properly tagged as such. Trying to find a thread where this is discussed, will update if I find it.
ETA: Discussed
here for DFW and MIA, will keep looking.
Also ETA: Found references
here and
here as well. The red tag is referred to as an "ITI" (international to international) tag.