The problem with that chart, hoot1, is that the average literacy rate doesn't show what's important here.The site which Bulk posted showed literacy by state and county. My grasp of this post illustrated to me that most states are fairly uniform in terms of literacy with a few counties being an exception.
Guess this shouldn't be surprising as state governments control education. The Dem v. Pub, and urban v. rural may be of less importance than one might think.
For example, if you had a county like Cook with a lot of very highly literate people and a lot of illiterate people, you might get an average looking county. But that's not important--we don't want highly literate people offsetting the illiterate for these purposes, because, for these purposes we don't care how many people can read and enjoy Shakespeare, we want to know how many people can't figure out or who have difficulty with routine activities we might take for granted that require basic literacy skills (e.g, maybe this is one reason why non-asian minorities have fewer photo IDs?).
That's why I think we want just a straight up binary comp.
Here's a more thorough brief on the issue that cites most of the things you'd expect: poverty, illiteracy in the family, etc. as factors associated with illiteracy. It also finds:
"Results of a nationally representative survey from 2003 [20] in combination with US Census data from 2000 [21] show correlations between illiteracy, low income, low levels of education, and unemployment. All of these issues are concentrated in Southern states and urban locations. Possible explanations for the intersectionality of race, poverty, age, and incarceration will be outlined in the following sections."
Illiteracy Among Adults in the United States - Ballard Brief
Illiteracy affects a person’s ability to fully contribute to the world around them. About 18% of the US adult population is functionally illiterate.
ballardbrief.byu.edu