National checks were done but not for as many jobs as we do them for today. Generally they were government jobs or corporate jobs related to the government. These were done with the government’s cooperation and were limited. You could pay a company to do a manual check in every state but this was imperfect and didn’t necessarily check records at the county level A big industry secret today is that the computerized checks don’t check every state because some are still not computerized and there is a need to verify the SS number and DOB because these are key. If the name and DOB match but the SS number is off or some similar, you need to go to the county where that offense occurred and manually check the record to see if that person is your job applicant. This is done by hiring a local company in that county to check it. Computer background checks are good but imperfect. They are much better than in the old days when you mostly did a local or state check. What we used to do is just manually check the counties or states where the applicant lived but then we missed arrests while the applicant was traveling. I used to own a company that did computer background checks.