This is a pretty good point. So there are different levels of literacy I’ve noticed. Sometimes, I’ve seen it referred to as just broadly unable to read and/or write a simple, short sentence while I’ve also seen it specifically clarified as below a specific grade level. There are also more official levels that can be read about more and you can read more about what each level is defined at. I remember coming across a pdf a while ago that broke up what each state’s literacy rate by each level was. Alabama was still ranked very low.

I imagine to get a rough estimate, you could say that you should try to account for immigrants by checking the proportion of illiterate people per population of both state and then also state minus immigrant population to see both. However, it doesn’t truly give us a very good idea because inaccurate immigrant count might lead to inaccuracies in known population and because I don’t know if it’s fair to says majority of all immigrants can’t read or write a simple sentence in English. There are lots of citizens who are immigrants and a fair amount of the citizenship test involves being able to read and study beforehand for example.

Edited a word.