No doubt that is true but it doesn't seem to account for the discrepancy, at least not without acquiring more data. Google's LLM is spitting out ~250K immigrant and first-generation Irish fighting in the Civil War, sitting roughly at 10% of the total. That doesn't account for second-generation and older, so I would be interested to see what social mobility was like for those more-established Irish-Americans: were they languishing in the working class, or did they exit from the middle class to go fight in wars disproportionately?

edit: how significant is the class factor, anyway? Does that model really apply, and how many citizens would be considered middle or upper class; enough to make a large statistical impact?

Google's LLM is an LLM. Results from an LLM are garbage unless you can test them. Any other sources?

Yes, I made sure to highlight that this was the (unreliable) source, consider it an invitation for the history buffs to chime in.

Food for thought: if I had posted the very first source available on Google as authorative, with no actual knowledge of my own to make the claim, that could be more misleading on aggregate, right?

Agreed, it's not so much where you find the source, but the source itself. Unquestioningly taking "first result" is just as bad as taking anything from an LLM and representing it as a factual answer. Also, kagi generally has higher quality search results (that can be checked).

Also we're not talking about the proportion of the entire nation that was Irish, we're discussing the fighting-age lower class population of the Union side only.