Just a suggestion here. Has anyone looked at the counties close by the areas you are interested in. All counties did not have schools and children did have to go long distances or, cross a bordering line. If you don't know where to start, I always call and talk to a human at the MS Archives. Sometimes you get more information than you asked for and they may be able to tell you about the time schedule to post this information. It doesn't hurt to call the ARCHIVES.
One other thing. I am researching, Monroe and Chickasaw Ms. There's only 1 year on this site for Monroe. BUT because many years ago I did a on site research trip, I have notes from records I found in the 1900's for my surnames. This information is in books with fading writing and you are only allowed to handle them in the confines of a special room. So copying them to the internet, may not be possible due to fragile handling. You tell the employees what pages you want, they copy them for you. ALWAYS, always ask for the page before and after your information. You will get home and see something vital may have been missed.
Some of us have a tendency to ignore the long existing white Mississippi societies. I have done so also. You need to understand, they have information and records from many, many years back. Eventually we all have to go to the x-slaveholders old 'written' information hoping for a piece of information about our own families. Their Genealogy and Historical Societies need new members. It is not necessary to attend meetings, especially if you don't live anywhere near the area. Your $$$ attends. This is where you can join for 1 year, the one of your choice, that has NEWSLETTERS sent to members. That's information you would have had to search for for that year. Add up the cost to do this-on site. 1 year. See what, if anything you get. Then move on, if nothing develops. Money talks. I had a society, I joined did not publish an article, I wrote for an ancestor that lived there. I did not rejoin this society. Don't you know I got an email asking me if I still wanted the article put in their newsletter. I said sure,--- but you know I am not going to send any money to them for membership renewal. They had 1 year.