Although the first public school act was passed under the Pease Administration in the mid 1850's the schools were basically community ones, there weren't 12 grades and there was no "pre-K".

I would suggest that first you find out exactly what was authorized under Texas law, and that you search Gammill's "Laws of Texas " at http://texinfo.library.unt.edu/lawsoftexas/default.htm

Although public schools were authorized, it was probably more common to have private schools or academies. About the only place that you are going to find information about actual schools is to browse Commissioners' Court minutes for the late 1850's.

It would appear to me that although public schools were authorized, the mentality of the time was for a community to establish and fund a school, and there was very little state aid, and certainly no "mandates."

Good luck.