Originally Posted by
AAaLot
I am not doubting you, but do you know legally why?
No, but it's been longstanding US law that you can't prohibit someone from leaving who wants to leave. I don't doubt that it's a reaction against historical governments that wouldn't let people travel without permission, just like some of the other freedoms that were traditionally taken for granted in this country were a reaction to things that were not allowed under British rule.