Originally Posted by
NickB
Do you have any particular US airline in mind? AFAIK, like AF, US airlines still stick to the old IATA 115cm across the 3 dimensions standard for the main carry on. The one difference is that (like Easyjet, incidentally) they do not impose a weight limit but that is not something an agent could see by looking at it (unless the passenger patently struggles to carry it).
DL do, but AF don't do linear any more - they do strictly 55x35x25, so for instance my brother was made to check in his musical instrument which was well below 114cm combined dimensions but long and thin.
In my experience, US airlines also do not count airport shopping bags and food/drinks (you can bring as much as you want) while European airlines count it as part of the allowance, at least officially. And finally, US airlines will often turn a blind eye on multiple cabin luggage for elite customers (I have seen some shocking scenes on AA) while there is no such benefit on most European airlines.
That said, clearly none of it applied in the OP's case, and even though he/she is not scandalised, I would be
