Here’s a timeline chart
https://usafacts.org/articles/how-many-people-work-for-the-federal-government/
Aside from immediately after FDR the federal government has been fairly steady at 3 million personnel. FDR tripled federal employees and its stuck like glue since.
What’s also interesting is the amount of DoD civilian employees has not changed since at least 1980 at around 800k employees, at the same time military personnel has dropped 39% in that same time period.
https://usafacts.org/articles/how-many-people-are-in-the-us-military-a-demographic-overview/
I can’t imagine anything other than set government bloat that has made a consistent need for 3 million personnel.
Technology should have obsoleted a lot of those positions due to increased efficiency. I don't think fed size needs to increase linearly with population size, even without technological advancements.
True, a guy with an Excel spreadsheet can probably do the jobs of 4-5 workers from the 1940s just by sheer calculation speed. Data tables with hundreds of thousands of entries are crunched in a few seconds max.
A lot of obsolete positions probably won't go away; unless DOGE goes after them at least. I've heard stories of people printing out spreadsheets or Word documents, then scanning them back in from the same device, then putting it into a PDF or embedding it into Excel and sending it to their boss. And their boss is a geriatric so they think it's a normal, reasonable process.
It's a lot easier to pretend to be busy when you have to and use the scanner all the time, looking important with a stack of papers walking around.
However, that also would be counterbalanced by the increase in government roles. For instance, there were zero federal employees managing airport security in 1940 vs. the 58K working for TSA today. Now multiply that by all the other new programs we have. Which isn't to say I agree with the government doing these things, but simply an explanation for why technology wouldn't decrease the size of the workforce.
My point being that it's popular to point at the number of federal employees and say "look at all those lazy assholes doing nothing and sucking off the government teet", but the reality is that we have roughly the same percentage of people in the federal government doing a great many more things than their counterparts in 1940. Even more so when you consider that the Defense Department has absolutely grown, so proportionally the other agencies have shrunk but have more things to do than ever.
The size of the federal workforce is ultimately a red herring. The question should really be: "what are the things the federal government is doing that are unlawful, or we just don't want them to do?". If you eliminate those functions, the employees doing them will be eliminated as well.