It is more than reasonable and safe to say that "whom" does not enjoy any sort of common use in American English conversation.
It is used in the news media. It might even be used for effect. It certainly is not part of everyday speaking in American English in the least. It is safe to say that it might never have been a part of everyday speaking in American English at all in the first place.
Canute,
Considering my comments, what would you say about "whom" in BE?
The word "whom" is not learned communicatively as other grammar words are. The word "whom" has to be taught. This is something to take note of.