I remember that, when did they stop it?
I tried to find an answer. A non-official source said sometime in the 70s. The Justice Department was ‘overwhelmed’ with paperwork and decided to drop the requirement. In any case, registration of aliens has been done in this country in the not-to-distant past.
18-year-old men are still required to ‘register’ with the government, but to require the same from people we don’t know is ‘unAmerican’?