[SoftTalker]

Nope. It was pretty common to have them and/or your SSN printed on your personal checks, and if they weren't, the merchants would often ask to see ID and write the numbers on the check themselves.

[judge2020]

Your SSN is “not for identification”, but with no national ID it became one anyways. https://images.app.goo.gl/NTMD5jGHsF27nbZRA

[quesera]

Not that many years ago, it was common for your drivers license ID number to be the same as your SSN!

[SoftTalker]

Yep. My SSN was also my student ID number when I was in college.