In my prior life, I spent a good deal of time in the late 60s at INS reviewing alien files as a part of the security screening afforded all aliens and naturalized citizens who were in the army. Besides maintaining huge files on each of them, they required each alien fill out a form the first of each January which stated where they were residing. The deportation process was working well too and frequently agents would go out and do “alien sweeps” and if they found those who over stayed visas or lied on applications or whatever, they would begin the deportation process. Frankly it seemed to work well. I don’t know why this was stopped after the early 70s but it should begin in earnest again.
After a while, Canadian framing crews started to show up illegally and were underbidding Americans for jobs.
Someone dropped a dime on them, raids ensued and the Canadians were deported.
Imagine that.