Passports and Vaccinations

Ok, so maybe the early Pentecostal missionaries such as my great-grandparents were a little naive. They did not think to get passports before leaving the U.S. They just bought a ticket and got on the boat and left for China without even getting shots or vaccinations. So how did they get all the way to China without proper documentation? By boat, obviously. The passenger lists tell the story. They were not natives of China obviously when the U.S. embassy discovered their presence and shipped them back to the U.S. if that is what happened though no one has yet explained this to me. So if we say that our great-grandparents were in China does that makes us Chinese? Does that make our currency the Mexican peso favored over the U.S. dollar or the "cash," a Chinese coin that has a square hole in it? No, actually not. No, it is not that complicated. It is actually a passport issue. A diplomatic stink. Something like that. They were there and we should be able to explain this without being treated like aliens from outer space in my humble opinion.