I’m interested in knowing this as well. I commented on the Module 6 spines thread about using “This Country of Ours” as a spine for high school American History. When you have different age levels together for a subject, I know the spine is typically on a lower level than high school; but you simply supplement with other books, etc. for the high school student. So I was wondering if that book would work well as the spine. I would think, though, there would probably need to be another spine to use for 20th century and beyond like you mentioned. I look forward to seeing what others have to say.
