Originally Posted by jrk1998
No problem. US Customs officals are only interested in US citizens with regard to having travelled to Cuba.
This is true, but...
I have two Cuba stamps in my US passport (I asked them to, as I was there legally). I have since carried around my authorization letter in case US immigration asked about it. Only once did an official even say a word about it, and then he did not even care much and was merely curious, let alone ask me to prove the legality of my visit.