In the 1800’s there was a mandatory draft of jews in Russia. Jews were drafted for 25 years, the jews who were taken were called cantonists.
Instead of direct draft by the government, the tsarist government made the local jewsish leader pick who went.
The Rich jews usually bribed their way out of letting their sons go and the Rabbis usually used their connections to get their sons out of the draft.
So the usual people taken were the poor unconnected especially the orphans who had no-one to vouch for them