The passports are much, much older then WWI - however railroads in late XIX century made travel requirements more relaxed as the administration were not able to

The passports are much, much older then WWI - however railroads in late XIX century made travel requirements more relaxed as the administration were not able to catch up with technology. Also XIX c. passports were without biometry (ie without photography of the holder). [1] https://en.m.wikipedia.org/wiki/Passport https://en.m.wikipedia.org/wiki/Passport