I just discovered that there are more classes available on line for high school that include works of Chesterton in their curriculum, a fact about which I am quite proud and glad.
The two I found are: English 1: The Short Story
English III/IV: The Christian Response to the Modern World: The Christian Response to Modern Scientism, which sound sparticularly intriguing.
To find these classes, click on the links above.
I'm pretty sure we can thank Martin Cothran for this, as he is a big Chestertonian and teaches at Memoria Press.