In 1910, the principal of James County High School, Mr.C.J. Doub, visited every elementary school in the county driving a horse and buggy because he was not the owner of the only automobile in James County. The roads were not in good condition for the use of an automobile, anyways. I wouldn't be surprised if that was the reason that nobody had invested in the new mode of transportation. He tried to promote the attributes of a higher education to the young students of these schools.
There are a few other schools that are not on this map. They may had already dissolved by 1921. We know of Fairview School that was located on current day Snow Hill Road. Honestville School was located near the current day Hunter Road and Birchwood School was located, of course, in Birchwood. There may even be more grammar schools that we are unaware of at this time.
With bad roads and no good means of transportation, one can understand why a person's education would stop before the high school level. Mr Daub had quite an uphill battle to convince parents to allow their children to attend the high school.