Correction: slavery in Russia/Soviet Union ended in 1974 when all the rural residents got passports and with it the right to leave the collective farm and change the profession.

Correction https://en.m.wikipedia.org/wiki/Emancipation_reform_of_1861

Serfdom ended in 1861.

There's a very good argument that, after being abolished in 1861, serfdom was re-introduced in the early 1930s via collectivization. Instead of private ownership of serfs, the state effectively owned the peasants who were bound to their collective farms by a system of meagre food-for-labour payments, needing permission to leave the farm/village for any reason, etc. The peasants that "came with" the collective farms were only issued internal passports in the late 1960s. Anyone who knows anything about life in the USSR understands the implications of having no internal passport. You didn't quite need one to breathe when outside your city/town/village, but just about.

Without an internal passport a person would be detained at the first train station and, in best case, returned back to the farm.

> Decades ago I read that at some point each feudal lord coined his own currency for his peasants. If a peasant escaped, he wouldn't have means to take anything with him.

A modern echo of this: Several times in the gloomy AM hours, I have worried what might happen if the current US administration tries to impose capital controls [0] like China. You might flee to Canada, only to find out that most/all of your life savings are forfeit to the tender mercies of the US government.

[0] https://www.reuters.com/markets/us/investors-could-exit-tari...