Thanks, I was vaguely aware that it was around the turn of the century that these things came in. An american in 1940 may not have needed a passport to leave,

Thanks, I was vaguely aware that it was around the turn of the century that these things came in. An american in 1940 may not have needed a passport to leave, but would they have needed one to get in somewhere else? Surely the nations of europe at that time would have been suspicious of basically everyone?