Why 1800s? Why not Roman times? All you had to do is state you were a roman citizen, and you could travel - Unimpaired “ Civis Romanus sum”

https://en.m.wikipedia.org/wiki/Civis_Romanus_sum

Borders existed but travel was not impaired, how else do you think trade and commerce worked? Do you think supply chains are a new thing?

It very much sounds like you are conflating serfdom, as an impairment to free travel - it is a different exercise. Because you did have a king, and you were a farmer in that land and in many ways you had lesser rights than a slave.

The Roman Empire was a unique example among the thousands of years of history because along with their transportation network of roads they did actually have a couple of passport-like systems in place. Now a third of the people were literally slaves, so they definitely weren't going anywhere without permission, so maybe Rome is not a great starting point for what I presume to be the argument against passports. But the Romans and other Mediterranean civilizations did check your identity when you travelled. Romans had documents they called diplomas for people on official business and several civilizations used clay tablets called tesserae as a sort of ID card, but by far the most common method was simply having known people vouch for you.

Basically nowhere in the ancient world from the Middle East to the pre-colonial Americas could you just show up in a foreign village without people asking questions that you ought better have good answers for. There are a handful of exceptions, but this has never been the norm, and even with passports and visa restrictions it is definitely far easier today than it ever was in the past. I expect it will get easier and easier into the future. Perhaps quite soon in fact as the global population begins to decline and people become more and more valuable.